ASIPP Neuroanatomy & Function Questions Flashcards

1
Q
  1. Cognitive and contextual aspects of the perceptual
    dimensions of pain appear to be processed in:
    A. The VPL region of the thalamus
    B. The periventrivcular grey region
    C. The inferotemporal and frontal cortical regions
    D. The hypothalamus
    E. None of the above
A
  1. Answer: C

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q
207. The reversible cholinesterase inhibitor indicated in the
treatment of Alzheimer’s disease is
A. Tacrine
B. Edrophonium
C. Neostigmine
D. Pyridostigmine
E. Ambenonium
A
  1. Answer: A
    Explanation:
    Reference: Katzung, p 1040.
    Patients with Alzheimer’s disease present with progressive
    impairment of memory and cognitive functions such as a
    lack of attention, disturbed language function, and an
    inability to complete common tasks. Although the exact
    defect in the central nervous system (CNS) has not been
    elucidated, evidence suggests that a reduction in
    cholinergic nerve function is largely responsible for the
    symptoms.
    Tacrine has been found to be somewhat effective in
    patients with mild-to-moderate symptoms of this disease
    for improvement of cognitive functions. The drug is
    primarily a reversible cholinesterase inhibitor that
    increases the concentration of functional ACh in the brain.
    However, the pharmacology of tacrine is complex; the
    drug also acts as a muscarinic receptor modulator in that
    it has partial agonistic activity, as well as weak antagonistic
    activity on muscarinic receptors in the CNS. In addition,
    tacrine appears to enhance the release of ACh from
    cholinergic nerves, and it may alter the concentrations of
    other neurotransmitters such as dopamine and NE.
    Of all of the reversible cholinesterase inhibitors, only
    tacrine and physostigmine cross the blood-brain barrier in
    suffi cient amounts to make these compounds useful for
    disorders involving the CNS. Physostigmine has been
    tried as a therapy for Alzheimer’s disease; however, it is
    more commonly used to antagonize the effects of toxic
    concentrations of drugs with antimuscarinic properties,
    including atropine, antihistamines, phenothiazines, and
    tricyclic antidepressants. Neostigmine, pyridostigmine,
    and ambenonium are used maily in the treatment of
    myasthenia gravis; edrophonium is useful for the
    diagnosis of this muscular disease.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q
  1. Regeneration of axons:
    A. Occurs in the segment distal to the damage
    B. Is independent of the survival of the perikaryon
    C. Includes a decrease in the volume of the perikaryon
    D. Is dependent on proliferation of Schwann cells
    E. Is initiated with an increase in production of Nissl substance
A
  1. Answer: D
    Explanation:
    (Junqueira, 9/e, pp 176-180. Kandel, 4/e, p 1108-1109.)
    Regeneration depends on the proliferation of Schwann
    cells, which guide sprouting axons from the proximal
    segment toward the target organ. This process is referred
    to as Wallerian regeneration. Axonal regeneration occurs in neurons if the perikarya survive following damage. The
    segment distal to the wound, including the myelin, is
    phagocytosed and removed by macrophages. The proximal
    segment is capable of regeneration because it remains in
    continuity with the perikaryon. Chromatolysis is the fi rst
    step in the regeneration process in which there is
    breakdown of the Nissl substance, swelling of the
    perikaryon, and migration of the nucleus peripherally
    Degeneration of perikarya and neuronal processes occurs
    when there is extensive neuronal damage. Transneuronal
    degeneration occurs only when there are synapses with a
    single damaged neuron. In the presence of inputs from
    multiple neurons, transneuronal degeneration does not
    occur.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q
  1. The alpha rhythm appearing on an electroencephalogram
    has which of the following characteristics?
    A. It produces 20 to 30 waves per second
    B. It disappears when a patient’s eyes open
    C. It is replaced by slower, larger waves during REM sleep
    D. It represents activity that is most pronounced in the
    frontal region of the brain
    E. It is associated with deep sleep
A
  1. Answer: B
    Explanation:
    (Guyton, pp 691-692.) In a totally relaxed adult with eyes
    closed, the major component of the electroencephalogram
    (EEG) will be a regular pattern of 8 to 12 waves per
    second, called the alpha rhythm. The alpha rhythm
    disappears when the eyes are opened. It is most prominent
    in the parieto-occipital region. In deep sleep, the alpha
    rhythm is replaced by larger, slower waves called delta
    waves. In REM sleep, the EEG will show fast, irregular
    activity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q
  1. The receptors responsible for measuring the intensity of
    a steady pressure on the skin surface are:
    A. Pacinian corpuscle
    B. Ruffi ni ending
    C. Merkel’s disk
    D. Meissner’s corpuscle
    E. Krause ending
A
  1. Answer: B
    Explanation:
    (Rhoades, pp 69-70.)
    B. The Ruffi ni ending is a tonic receptor that produces a
    train of action potentials proportional to the intensity of
    pressure applied to the skin.
    A. The Pacinian corpuscle is a very rapidly adapting
    receptor that fi res once or twice in response to skin
    deformation.
    It can produce a continuous train of action potentials if
    the stimulus is repetitively applied and withdrawn.
    Therefore, the Pacinian corpuscle is used to encode
    vibration.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
211. Which of the following nerve fi bers is not myelinated?
A. A alpha fi bers:
B. A delta fi bers
C. A gamma fi bers
D. B fi bers
E. C fi bers
A
  1. Answer: E

Source: Day MR, Board Review 2004

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
212. Mechanical nociception appears to be predominantly
modulated by:
A. The raphe-spinal system
B. The ceruleo-spinal system
C. The GABAergic system
D. All of the above
E. None of the above
A
  1. Answer: B

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q
  1. Rubbing or patting a painful area can often reduce the
    sensations of pain.This is due, at least in part, to:
    A. High-threshold C-fi ber overload
    B. Depletion of Substance-P within primary nocisponsive
    afferents
    C. Stimulation of the dorsal columnar/medial lemniscal
    pathway
    D. Provocation of a vasoconstrictive response to reduce local
    hyperemia
    E. None of the above
A
  1. Answer: C

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
  1. The nodes of Ranvier:
    A. Occur only in the CNS
    B. Contain few Na+-gated channels
    C. Represent the midpoints of myelination segments
    D. Are completely covered by myelin
    E. Increase the effi ciency of nerve conduction
A
  1. Answer: E
    Explanation:
    (Junqueira, 9/e, pp 170, 171,174. Kandel, 4fe, pp21-22,
    148, 160.)
    B. Most of the Na+ -gated channels are located in the bare
    areas.
    Therefore, spread of depolarization from the nodal
    region along the axon occurs until it reaches the next node.
    This is often described as a series of jumps from node to
    node, or saltatory conduction.
    C. The nodes of Ranvier represent the space between
    adjacent units of myelination.
    D. This area is bare in the CNS, whereas in the PNS the
    axons in the nodes are partially covered by the cytoplasmic
    tongues of adjacent Schwann cells.
    E. The nodes of Ranvier increase the effi ciency of nodal
    conduction because of restriction of energy-dependent
    Na+ infl ux to the node.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q
215. Properties of pain stimulus modality and anatomic
localization are primarily conveyed along which afferent
pathway?
A. Neospinothalamic tract
B. Paleospinothalamic tract
C. Medial lemniscal tract
D. None of the above
E. All of the above
A
  1. Answer: A

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  1. The cells responsible for the entry of human
    immunodefi ciency virus (HIV) into the CNS are
    A. Microglial macrophages
    B. Astrocytes (astroglia)
    C. Oligodendrocytes (oligodendroglia)
    D. Endothelial cells
    E. Schwann cells
A
  1. Answer: A
    Explanation:
    (Kandel, 4/e, p 20. Braunwald, 15/e, pp 1873, 1890-1891.)
    Microglia are the macrophages of the brain. They become
    infected with HIV and carry the virus into the CNS. The
    virus remains latent until a stimulus activates viral
    production. These cells are the most conspicuous elements
    of HIV-induced CNS pathology. Infection, proliferation,
    and fusion of microglia/macrophages appear to be
    involved in the development of giant cell encephalitis of
    acquired immune defi ciency syndrome (AIDS) and other
    pathologies associated with neuronal damage in AIDS
    dementia. The CNS effects of AIDS are extensive as
    indicated by the fact that 90% of AIDS patients show
    abnormalities in the cerebrospinal fl uid (CSF), even in
    asymptomatic stages of the disease.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  1. Discriminatory localization and intensity of pain appear
    to be primarily processed in which supratentorial area?
    A. Hypothalamus
    B. VPL thalamus
    C. Reticular formation
    D. Primary somesthetic cortex
    E. All of the above
A
  1. Answer: D

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  1. Activation of transducin by light activates an enzyme
    which
    A. Hydrolyzes cGMP
    B. Increases the dark current
    C. Activates adenyl cyclase
    D. Releases calcium from intracellular stores
    E. Depolarizes the membrane
A
  1. Answer: A
    Explanation:
    (Rhoades, pp 73-76.) Transducin is the G protein that
    mediates the response to light by rods and cones in the eye. When transducin is activated, it activates an enzyme that hydrolyzes cyclic GMP (cGMP). In the dark, cGMP binds
    to Na+ channels, keeping them open. The fl ow of Na+
    through these channels keeps the rods and cones
    depolarized. The activation of transducin by light and the
    subsequent hydrolysis of cGMP cause the Na+ channels to
    close and the membrane to hyperpolarize.
    Hyperpolarization of the membrane prevents the release
    of an inhibitory transmitter by the rods and cones, which
    ultimately results in stimulation of optic nerve fi bers and
    the awareness of a visual image.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
  1. Which one of the following hypothalamic nuclei is
    responsible for the detection of the core body
    A. The lateral hypothalamus
    B. The arcuate nucleus
    C. The posterior nucleus
    D. The paraventricular nucleus
    E. The anterior hypothalamus
A
  1. Answer: E
    Explanation:
    (Guyton, pp 826-830.) The hypothalamus regulates body
    temperature. Core body temperature, the temperature of
    the deep tissues of the body, is detected bythermoreceptors
    located within the preoptic area and the anterior
    hypothalamic nuclei. The preoptic area also contains
    neurons responsible for initiating refl exes, such as
    vasodilation and sweating, which are designed to reduce
    body temperature. Heat -producing refl exes, such as
    shivering, and head maintenance refl exes, such as
    vasoconstriction, are initiated by neurons located within
    the posterior hypothalamus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q
  1. When an axon is cut, rapid local degeneration of the
    axon and myelin sheath occur, as well as changes in the
    cell body that affect synapses with other neurons. This
    pattern of degeneration is caused by
    A. Gliosis
    B. Axonal transport
    C. Phagocytosis
    D. Excitatory neurotransmitters
    E. Depolarization
A
  1. Answer: B
    Explanation:
    (Kandel, pp 730-735.)
    When the axon is cut, the axon and synaptic terminals
    are deprived of essential metabolic connections with the
    cell body. With axonal transport in both directions, there is
    a rapid local degeneration of the axon and myelin sheath,
    with the cell body also being affected.
    Synapses mediate both electric signals and nutritive
    interactions between neurons. Thus, changes occur in the
    cell body (retrograde changes) and also in subsequent
    neurons that receive synapses from the damaged neurons.
    Macrophages from the general circulation enter the
    trauma area and phagocytose axonal debris, and glial
    cells (astrocytes and microglia) proliferate to assist in the
    process. This proliferation of fi brous astrocytes forms a
    glial scar around the trauma area, which can then block
    the course of regenerating axons and the reformation of
    central connections.
    The behavioral effects of nerve lesions are peculiar to
    the location of the lesion in the brain and the nerve cell
    connections, so the same type of injury will have different
    behavioral effects depending on its location
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q
  1. What is the principal role of the descending serotonergic
    system in pain processing?
    A. Activation of polysynaptic interneuronal systems within
    the spinal analgesic neuraxis
    B. Direct inhibition of primary and second-order afferent
    fi bers within the dorsal horn of the spinal cord
    C. Both of the above
    D. None of the above
A
  1. Answer: C

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q
  1. As a general practice
    A. Opiate maintenance dosing should be discontinued
    prior to trial of SCS
    B. Antibiotics prophylaxis should be delivered when implanting
    devices
    C. Patients should be considered for neurostimulation
    without a preoperative psychological assessment
    D. Intrathecal drug delivery should be initiated with ziconotide
    as a primary infusion
    E. Trial of patients for chronic neuromodulation should not
    be done by the individual who will maintain the device
A
  1. Answer: B

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q
  1. In skeletal muscle contraction, the “powerstroke” is
    initiated by
    A. The initial binding of ATP to the myosin heads
    B. Release of Pi from the myosin heads
    C. Detachment of the myosin head from the actin
    D. Phosphorylation of the myosin light chains
    E. Release of ADP and subsequent addition of an ATP molecule
A
  1. Answer: B
    Explanation:
    (Alberts, 3/e, pp 851-853. Junqueira, 9/e, pp 185-190.) The
    “powerstroke” is initiated by the release of Pi from the
    myosin heads, leading to the tight binding of actin and
    myosin. The tight binding induces a conformational
    change in the myosin head. The myosin head subsequently
    pulls against the actin fi lament to cause the “powerstroke”
    of the myosin head walking along the actin fi lament. This
    walking process is unidirectional and is based on the
    polarity of the actin fi lament (i.e., walking occurs from the
    minus to the plus end of the actin fi lament). The cycle of
    ATP-actin-myosin interactions during contraction begins
    with the resting state. In the quiescent period,ATP binds to
    myosin heads; however, hydrolysis occurs slowly and only
    allows the weak binding of myosin heads to the actin
    fi laments. Tight binding occurs only when Pi is released
    from myosin heads, leading to the “powerstroke.”
    Recycling occurs through the release of ADP and the
    subsequent addition of an ATP molecule and detachment
    of the myosin head from actin. Rigor results from the lack
    of ATP because one ATP molecule is required for each
    myosin molecule present in the muscle. Rigor mortis
    occurs from the total absence of ATP.
    Myosin is composed of two coiled heavy chains and four
    light chains.
    It may be separated into heavy and light meromyosin by
    enzymatic treatment. Heavy meromyosin has two
    segments: S1 (the globular head region) and S2. The S1
    subfragment includes the light chains that are associated
    with the globular head regions. This region is signifi cant
    because it is the site of the actin binding that activates
    ATPase activity. S2 is a dimeric population of the myosin
    molecule that connects the two S1 segments to the coiled
    light meromyosin subunit. The P light chain is one of the
    two light
    chains associated with the globular heads and is
    phosphorylated by myosin light chain kinase. In skeletal
    muscle, phosphorylation of the light chain is not required
    for binding to actin.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q
224.The striatum is formed by all of the following structures
EXCEPT the
A. Caudate nucleus
B. Globus pallidus
C. Olfactory tubercles
D. Nucleus accumbens
E. Substantia innominata
A
  1. Answer: B
    Explanation:
    The striatum is the main receiving station for the basal
    ganglia. It receives massive projections from all areas of
    the cerebral cortex and from certain thalamic nuclei, the
    substantia nigra, and other brain stem nuclei. The caudate
    nucleus and the putamen are the largest of the nuclei
    composing the striatum.The ventral striatum consists of
    the ventral portion of the caudate nucleus, the putamen,
    the deep layers of the olfactory tubercle, the nucleus
    accumbens, and the substantia innominata. Although the
    nucleus accumbens and the substantia innominata are
    frequently referred to as parts of the olfactory system, they
    play an important functional role in the basal ganglia.
    (Afi fi and Bergman, 275-294)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

225.The ascending noradrenergic pathway can engage
sympathetic nervous system function
A. Only through indirect activation of preganglionic sympathetic
neurons
B. Only by direct activation of sensory associative areas in
the S-II somatosensory cortex
C. Via inhibition of the insular-anterior cingulate pathway
D. Only by engaging the thalamic intralaminar nucleus
E. By engagement of amygdalar, insular and hypothalamic
paraventricular substrates

A
  1. Answer: E
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch4. Spinal
    mechanisms and modulation.The ascending noradrenergic
    pathway is activated via input from the paleo-spinal
    thalamic tract. Ascending noradrenergic fi bers from the
    reticolumagnocellular group (RMC), together with PSTT
    fi bers project to the parabrachial nucleus to engage the
    amygdala, insula, cingulate and ultimately, hypothalamic
    paraventricular nucleus to evoke sympathetic nervous
    system activity. As well, the intra-laminar nucleus of the
    thalamus can be activated by both NEneurons of the RMC
    and the PSTT to engage hypothalamic-sympathetic
    activation. Thus, multiple pathways can be activated by the
    ascending NE tracts to act singularly or in concert through
    the hypothalamus to engage sympathetic neural output.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q
  1. Which of the following is (are) true?
    A. Neurostimulation is appropriate in patients with PVD
    B. Neurostimulation is not appropriate in patients with
    angina
    C. Neurostimualtion is useful in all patients with low back
    pain.
    D. All of the above.
    E. Two of the above
A
  1. Answer: E

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q
  1. Neuromodulation should be considered in patients who
    have no other remaining therapeutic opportunities.
    A. If they have a life expectancy of greater than one
    month.
    B. If the pain is in the back, not the extremity
    C. If the pain is in the leg but not the back.
    D. If the pathophysiology is appropriate for the therapy.
    E. If the patient’s insurance will cover the procedure
A
  1. Answer: D

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  1. Contrasting neurostimulation with intraspinal drug
    delivery:
    A. Neurostimulation is superior in the treatment of neuropathic
    pain phenomenon.
    B. Intraspinal drug delivery has a higher rate of signifi cant
    complications
    C. Intraspsinal drug delivery is superior in the treatment
    of nociceptive pain phenomenon
    D. All of the above.
A
  1. Answer: D

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  1. The EKG of a patient who is receiving digitalis in the
    therapeutic dose range would be likely to show
    A. Prolongation of the QT interval
    B. Prolongation of the PR interval
    C. Symmetric peaking of the T wave
    D. Widening of the QRS complex
    E. Elevation of the ST segment
A
  1. Answer: B
    Explanation:
    Reference: Hardman, pp 813-814.
    The usual electro cardiographic pattern of a patient
    receiving therapeutic doses of digitalis includes an
    increase in the PR interval, depression and sagging of the
    ST segment, and occasional biphasia or inversion of the T
    wave. Symmetrically peaked T waves are associated with
    hyperkalemia or ischemia in most cases. Shortening of the
    QT interval, rather than prolongation, is characteristic of
    digitalis treatment.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q
230. Failed back surgery syndrome patients should be
considered for SCS:
A. If that is their diagnosis
B. If they hurt in their back
C. If they hurt in their leg
D. If they have neuropathic pain
E. If they have segmental instability
A
  1. Answer: D

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q
  1. Lissauer’s tract is:
    A. Composed of A-delta and C-fi bers which are ascending
    and descending in the superfi cial apex of the dorsal
    horn prior to synapsing with dorsal horn interneurons.
    B. The lateral ascending spinal tract which connects dorsal
    horn interneurons to supraspinal centers.
    C. The posterior descending tract which connects inhibitory
    supraspinal centers to dorsal horn neurons
    D. The tract which transmits pain signals from one side of
    the spinal cord to the other
    E. Connects post-ganglionic sympathetic fi bers to the spinal nerve.
A
  1. Answer: A
    Explanation:
    Reference:
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Spinal Mechanisms and their Modulation. pp. 74-76.
    A. Lissauer described a tract running in the superfi cial
    apex of the dorsal horn that differed in microscopic
    appearance from the rest of the cord. Ablation of this tract
    created analgesia in experimental animals. Later study
    revealed that this tract contained the axons of A-delta and
    C-fi bers that were entering the cord from the periphery.
    These fi bers ascended and descended for one or more
    segments in the tract prior to synapsing with dorsal horn
    interneurons.
    B. The lateral spinothalamic tract and other ventrolateral
    cell columns connect dorsal horn interneurons to
    supraspinal centers.
    C. The posterior spinal columns transmit mainly tactile
    information from large, fast conducting A-beta fi bers.
    E. Pre-ganglionic sympathetic fi bers enter the sympathetic
    ganglion via the gray rami communicantes while postganglionic
    sympathetic fi bers exit the ganglion and enter
    the spinal nerve through the white rami communicantes.
    Source: Schultz D, Board Review 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q
  1. Catheter tip granuloma:
    A. Have been reported to occur with morphine infusion
    B. Is thought to occur in at least 1% of the pump population.
    C. Must be treated surgically
    D. All of the above.
    E. Two of the above.
A
  1. Answer: E

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q
233. FDA approved indications for SCS include
A. CRPS 1
B. CRPS 2
C. Angina
D. Two of the above
E. None of the above
A
  1. Answer: E

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q
234. Chronic Intraspinal drug delivery most commonly is
accomplished with:
A. One drug
B. Two drug
C. Three drug
D. Non-programmable pump
E. An epidural catheter
A
  1. Answer: A

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q
  1. Paddle leads offer which of the following advantages over
    percutaneous leads:
    A. Increased power requirements
    B. Decreased paresthesia overlap for an equivalent array
    C. Greater array stability
    D. Facilitated implant method
    E. User fl exibility in array construction
A
  1. Answer: C

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q
236. The principal efferent neuron layer of the cerebral
neocortex is
A. II
B. III
C. IV
D. V
E. VI
A
  1. Answer: D
    Explanation:
    The cerebral neocortex has a laminar pattern of
    organization because of the distribution and size of
    neuronal cells and the horizontal pattern of incoming
    efferents. It is divided into six layers: Layer I,. primarily a
    synaptic area, is the molecular layer. It is the most
    superfi cial layer of the cerebral cortex; its most
    characteristic cells are horizontal cells.Layer II,the external
    granular layer, is characterized by an abundance of
    small, densely packed neurons and a paucity of myelinated
    fi bers. The dendrites of neurons in this layer project to
    layer I, while their axons project to deeper layers. Layer III,
    the external pyramidal layer, contains medium-large
    pyramidal cells and granule cells. Axons of most
    pyramidal cells descend through the cortex, forming
    cortical association fi bers, both callosal and
    intrahemispherical. Layer IV, the internal granular layer, is
    the principal receiving station of the cerebral cortex.
    Layer V, the internal pyramidal layer, is the principal
    efferent layer of the cortex. This layer contains pyramidal
    cells that send their axons through the cortical white
    matter to the internal capsule and all subcortical sites
    except the thalamus, which receives fi bers from Layer VI.
    Layer VI, the fusiform layer, contains fusiform and
    pyramidal cells, which are the principal source of
    corticothalamic fi bers and contribute to the
    intrahemispheric cortical association fi bers. (Afi fi and
    Bergman, 340-343; Burt, 451-452)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q
  1. In muscular dystrophy, the actin-binding protein
    dystrophin is absent or defective. Dystrophin contains
    similar actin-binding domains to the spectrins (I and
    II) and a-actinin and has a similar function. Which of
    the following is most likely to occur as a result of this
    defi ciency?
    A. Defi ciency in skeletal muscle actin synthesis
    B. Enhanced smooth muscle contractility
    C. Loss of binding of the I and M bands to the cell membrane
    D. Loss of organelle and vesicle transport throughout the
    muscle cell
    E. Loss of integrity of the desmosomal components of the
    intercalated discs of cardiac muscle
A
  1. Answer: C
    Explanation:
    (Alberts, 31e, p 855. Braunwald, 15/e pp 2529-25. Kumar, 6/e, pp 689-690.) Dystrophin, like these other actinbinding
    proteins, binds actin to the skeletal muscle
    membrane and, therefore, binds I and M bands to the cell
    membrane. The inability to bind actin to
    plasma membrane of skeletal muscle leads to disruption of
    the contraction process, weakness of muscle, and
    abnormal running, hopping, and jumping. Gowers’
    maneuver is the method used by persons suffering from
    muscular dystrophy to stand from a sitting position.
    Respiratory failure occurs in these persons because of
    disruption of diaphragmatic function.Dystrophin is found
    in muscle of all types and is part of a complex that
    regulates interactions of the sarcolemma with the
    extracellular matrix through associated glycoproteins
    (dystrophin -glycoprotein complex). Therefore, loss of
    dystrophin causes a destabilization of the sarcolemma.
    Muscular dystrophy refers to a group of progressive
    hereditary disorders (1/3500 male births) that involve
    mutations in the dystrophin gene. Dystrophin is similar in
    structure to spectrins I and II and a-actinin. Dystrophin is
    absent in Duchenne muscular dystrophy. Becker muscular
    dystrophy is a less severe dystrophy in which dystrophin is
    defective. Synthesis of actin is not reduced in skeletal
    muscle from these patients; in fact, hypertrophy and
    pseudohypertrophy (replacement of muscle with
    connective tissue and fat) occurs. Microtubules perform
    vesicular and organelle transport functions, and
    intermediate fi laments not actin form the intracellular
    connection in desmosomes.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  1. In patient who has had attacks of paroxysmal atrial
    tachycardia, an ideal prophylactic drug is
    A. Adenosine
    B. Procainamide
    C. Lidocaine
    D. Nifedipine
    E. Verapamil
A
  1. Answer: E
    Explanation:
    Reference: Hardman, pp 858-874
    Because verapamil, a Ca channel blocker, has a selective
    depressing action on AV nodal tissue, it is an ideal drug for
    both immediate and prophylactic therapy of
    supraventricular tachycardia (SVT). Nifedipine, another
    Ca channel blocker, has little effect on SVT. Lidocaine and
    adenosine are parenteral drugs with short half-lives and,
    thus are not suitable for prophylactic therapy.
    Procainamide is more suitable for ventricular arrhythmias
    and has the potential for serious adverse reactions with
    long-term use.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q
239. The FDA approved drugs for chronic intrathecal drug
delivery through a pump are:
A. Morphine
B. Bupivicaine
C. Lioresal
D. Prialt
E. Three of the above
A
  1. Answer: E

Source: Feler C, Board Review 2005

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q
  1. Following exposure to acute high threshold thermal
    stimulation, what event is likely in local population(s) of
    C-fi ber afferents?
    A. Rightward shift in their response curve
    B. Leftward shift in their response curve
    C. A prolonged latency period during which they are nonresponsive
    D. All of the above
    E. None of the above
A
  1. Answer: B
    Explanation:
    C-fi bers show sensitization following exposure to acute
    thermal stimli; this leads to enhanced temporal activation
    and a decrease in sensitivity threshold to both noxious and
    non-noxious stimuli.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q
  1. In primary nociceptive afferents, excitatory conduction
    is mediated by
    A. A-2 purinoreceptors
    B. Trk B receptors for nerve growth factor
    C. Selective Na (v)1.8 and Na (v)1.9 cationic channels
    D. The Silent Nociceptor which is not sensitized
    E. All of the above
A
  1. Answer: C
    Explanation:
    There are specifi c sodium channels that mediate the propagation and conductance of the action potential in
    nociceptive afferents; these have been identifi ed using
    molecular biological techniques that have elucidated their
    transcriptional and translational precursors.
    A-2 purinoreceptors subserve the transduction of the
    nociceptive signal in response to adenosine.
    Trk B receptors subserve the transduction of the
    nociceptive signal in response to BDNF.
    A Silent Nociceptor exists, but, is very diffi cult to activate
    under normal circumstance. Easily activated after
    sensitization.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q
  1. The projections of A-delta primary afferents
    A. Is identical to C-fi ber afferents
    B. Is Multilaminar within the superfi cial dorsal horn
    C. Is exclusive to wide dynamic range neurons
    D. A-Delta primary afferents project to laminae III, V and
    X
    E. All of the above
A
  1. Answer: B
    Explanation:
    A-delta primary afferents project to laminae I, II, and IIa
    of the dorsal horn.
    This is anatomically distinct from the projection sites of
    C-fi bers in that C-fi bers project to lamina V and not I.
    A-delta fi bers appear to form synaptic contacts exclusively
    upon NS second order neurons.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q
243. The neurochemical effect of the 17 amino acid peptide
dynorphin (1-17) is post- synaptically mediated by which
receptor?
A. Mu type 1
B. Delta
C. Kappa
D. Mu type 3
E. Mu type 2
A
  1. Answer: C
    Explanation:
    Dynorphin is the selective endogenous ligand at the kappa
    opioid receptor. Endorphins and met-enkephalin are the
    endogenous ligands at mu 1 and 2 receptors.
    Leu-enkephalin and to a lesser extent, endorphin, are the
    endogenous ligands at delta opioid receptors.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q
244. The majority of opioid receptors in the lumbar spinal
cord are:
A. Mu-1 and /or 2
B. Delta and Kappa
C. Sigma
D. Mu-3
E. Mu-2
A
  1. Answer: B
    Explanation:
    Autoradiographic, pharmacologic, and molecular biologic
    investigations have shown that the lumbar spinal cord
    contains primarily delta and kappa type opioid receptors.
    Mu opioid receptors are found in highest concentration in
    the midbrain, forebrain, and rostral (cervico-thoracic)
    spinal cord. Mu-3 receptors have been localized to smooth
    muscle and leukocytes.
    Sigma (PCP) receptors are primarily supratentorial.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q
  1. Which is not a projection site of the neospinothalamic
    tract neurons that subtend painful afferent volleys?
    A. Nucleus reticularis gigantocellularis
    B. Nucleus raphe Magnus
    C. Periaqueductal grey region
    D. All of the above
    E. None of the above
A
  1. Answer: D
    Explanation:
    The NSTT is a direct pathway to the thalamus.
    The paleospinothalamic tract (PSTT) projects to the
    brainstem raphe and magnocellular nuclei as well as the
    mesencephalic PAG region en route to its thalamic
    terminations.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q
246. In assessing and characterizing pain, the most useful
distinctions about the typology of pain can best be made
according to:
A. Physiological characteristics
B. Temporal characteristics
C. Subjective characteristics
D. Radiological Investigations
E. Nerve Conduction studies
A
  1. Answer: A
    Explanation:
    Physiologic distinctions (eg. nociceptive versus
    neuropathic)are useful referents that describe the nature of
    pain relevant to its typologic classifi cation.
    Temporal characteristics (immediate, acute, chronic) are
    often laden with ambiguity regarding relative length of time and are of little use in classifying the functional or
    pathologic basis of pain.
    Subjective characteristics are useful referents in describing
    the cognitive dimensions of pain, but may not directly
    refl ect underlying neural processes that are explicitly
    relevant to pathology for clinical purposes.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q
247. The patient who favors a particular area and moves
compensatorily to (reduce) pain sensation is said to be
exhibiting:
A. Guarding
B. Allodynia
C. Antalgia
D. Hyperalgesia
E. Dystocia
A
  1. Answer: C
    Explanation:
    A. Guarding is a patient’s reactions to protect or retract a
    painful bodily region against contact or insult.
    B. Allodynia is the sensation of pain produced by nonnoxious
    stimuli and occurs as a consequence of peripheral
    and/or central sensitization.
    C. Antalgia literally translates as “against pain” and is any
    posture or movement that functions to prevent
    provocation of nociception.
    D. Hyperalgesia is hypersensivity to a painful stimulus
    dysthesia is unpleasant abnormal sensation.
    E. Dystilosia is abnormal or diffi cult labor.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q
  1. Which of the following is involved in glomerular
    fi ltration?
    A. Facilitated diffusion of large anionic proteins
    B. Maintenance of a charge barrier
    C. A physical barrier consisting of type II collagen
    D. Filtration slits between adjacent endothelial cells
    E. A positive charge in the basement membrane due to the
    presence of heparan sulfate
A
  1. Answer: B
    Explanation:
    (Junqueira, 9/e, pp 360-364, 372-373.) The glomerular
    fi ltration barrier is a physical and charge barrier that
    exhibits selectivity based on molecular size and charge.
    The barrier is formed by three components: (1)
    glomerular capillary endothelial cells, (2) glomerular
    basement membrane, and (3) podocyte layer. The presence
    of collagen type IV in the lamina densa of the basement
    membrane presents a physical barrier to the passage of
    large proteins from the blood to the urinary space.
    Glycosaminoglycans, particularly heparan sulfate, produce
    a polyanionic charge that binds cationic molecules.
    Filtration slits are found between adjacent podocyte foot
    processes and provide a gap of approximately 50 μm. The
    foot processes are coated with a glycoprotein called
    podocalyxin, which is rich in sialic acid and provides
    mutual repulsion to maintain the structure of the fi ltration
    slits. It also possesses a large polyanionic charge for
    repulsion of large anionic proteins.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q
  1. A known NMDA/Glutamate receptor antagonist agent,
    such as topiramate would be most useful against:
    A. A-delta mediated thermal pain
    B. C-fi ber mediated neuropathic pain
    C. C-fi ber mediated mechanical nociceptive pain
    D. A-delta mediated cold
    E. All of the above
A
  1. Answer: B
    Explanation:
    C-fi ber mediated neuropathic pain is primarily subserved
    by glutamate-induced activation of both NMDA and
    mGlu receptors
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q
  1. A lesion of the axons of motor neurons that innervate
    skeletal muscle (lower motor neurons) will result in
    which one of the following consequences?
    A. Paralysis of individual muscles on the contralateral side
    of the lesion
    B. A paradoxical increase in refl ex activity
    C. Compensatory increase in muscle mass
    D. Increase in muscle tone
    E. Sealing off of the axoplasm
A
  1. Answer: E
    Explanation:
    (Kandel, pp 1108-1109.) The cutting of a nerve tract
    within the brain or of a peripheral nerve results in the following sequence: both ends of the cut axon immediately
    seal off the axoplasm, retract, and begin to swell; there is
    rapid degeneration of the axon and the myelin sheath; the
    macrophages from the general circulation enter the area
    and phagocytose axonal debris; there is also a proliferation
    of glial cells, which act as phagocytes; and fi brous
    astrocytes proliferate in the central nervous system,which
    leads to glial scar formation around the zone of trauma
    that often blocks the course taken by regenerating axons
    and causes a barrier against the reformation of central
    connections. Degeneration spreads along the axon in both
    directions from the zone of trauma. The retrograde
    reaction in the proximal segment usually progresses a
    short distance and appears in the cell body after 2 to 3
    days.
    In the distal segment, degeneration appears in the axon
    terminal in about I day, and within 2 weeks the distal
    synapses degenerate completely.
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q
  1. One of the factors that contributes to the induction of
    Type-II pain is:
    A. “Un-masking” of post-synaptic NMDA receptors within
    the algesic neuraxis
    B. Down-regulation of AMPA receptors within the spinal
    neural circuit
    C. Increased serotonergic output from the nucleus reticularis
    D. All of the above
    E. None of the above
A
  1. Answer: A
    Explanation:
    Glutamate-induced activation of post-synaptic AMPA
    receptors “ungates” an ionotropic NMDA receptor that is a
    functional substrate of type II pain.
    AMPA receptors do not appear to be sensitized or
    regulated as a consequence of continued exposure to
    glutamate.
    Serotonin is produced primarily in neurons of the raphe
    nulei, not the nucleus reticularis; increased output of
    bulbospinal serotonergic neurons produces analgesia.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q
  1. C-fi ber primary afferents
    A. Subtend transmission of Polymodal high threshold
    stimuli
    B. Subtend transmission of high threshold thermal input
    only
    C. Project exclusively onto Nociceptive specifi c second-order
    afferents
    D. Project exclusively onto wide dynamic range neurons
    E. All of the above
A
  1. Answer: A
    Explanation:
    C-fi bers respond to high threshold thermal, mechanical,
    and noxious chemical stimuli.
    C-fi bers project to laminae II, IIa, and V and synapse upon
    both NS and WDR second order neurons.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q
  1. Acute, nociceptive pain:
    A. Characteristically causes de novo expression of alpha
    adrenergic receptors in dorsal root ganglia
    B. Decreases activity in bulbospinal pathways
    C. Decreases adrenomedullary effects
    D. Can engage sympathetic function to suppress pain perception
    through bulbospinal and limbic noradrenergic
    mechanisms
    E. Induces decreased activity in ventral posterior lateral
    and medial nuclear groups of the thalamus
A
  1. Answer: Answer D
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 4. Spinal
    mechanisms and modulation.
    Acute nociceptive pain can engage bulbospinal
    (descending) and ascending noradrenergic pathways to the
    limbic system to suppress pain sensation and perception
    through inhibition of afferent dorsal horn input and
    supratentorial, “attentional analgesia” respectively. Such
    pain does not lead to novel expression of alpha adrenergic
    receptors in the periphery or DRG, as is commonly seen in
    chronic pain.Acute nociceptive pain can enhance
    activation of the adrenal medullary system, causing a
    release of adrenal opioids that subsequently produce
    analgesia.As well, such pain directly engages the
    neo-and paleo-spinal thalamic tracts to activate the
    ventralposteriolateral and medial thalamic nuclei,
    respectively.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q
  1. The following is true regarding nitric oxide (NO):
    A. It is a large molecular neurotransmitter that is actively
    transported across neural membrane
    B. It induces potent vasoconstriction and is inhibitory to
    infl ammatory pain
    C. It is a direct product of phosopholipase-A
    D. It is localized only within the vascular endothelium
    E. It is a rapidly synthesized, small molecular modulator
    that is produced in peripheral and central neurons and
    can easily diffuse into non-neural tissues
A
  1. Answer: E
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasiticity. Nitric oxide
    is a small gaseous molecule that is rapidly synthesized in
    neural and vascular endothelial tissue via convergent
    pathways that ultimately increase the catalytic activity of
    nitric oxide synthase. NO easily and passibly diffuses
    across neural and vascular membranes and can engage
    second messenger signaling systems to initiate
    vasodilatation and promote infl ammation and resultant
    infl ammatory pain.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q
  1. One mechanism through which sympathetic and
    nociceptive afferent fi bers can be cross-sensitized is
    A. Through remodeling of C-fi ber projections into spinal
    sympathetic ganglia
    B. By increased production of cyclo-oxygenase-2 in sympathetic
    pre-ganglionic fi bers
    C. Through ephaptic conduction and/or ionic spread
    D. By down-regulation of alpha adrenergic receptors on
    peripheral C-fi bers
    E. By retraction of C- and A-beta fi ber terminals from
    lamina VII
A
  1. Answer: C
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasiticity. Also Bonica’s
    Management of Pain,3rd Ed: Ch 4. Spinal mechanisms and
    modulation. Nociceptive afferents and sympathetic fi bers
    are frequently anatomically co-located, and adjacent
    within the dorsal root ganglia and peripheral nerve trunks.
    As well, peripheral tissue insult can produce a pathologic
    intermingling of nociceptive afferent and sympathetic
    fi bers both in neuromas and in non-neuromatous insult.
    These anatomically adjacent fi bers can, and frequently do
    permit ephaptic conduction signal transmission through
    low resistance zones and by ionic spread through shared,
    transmembrane ion channels. C-fi ber projections do not
    remodel into spinal sympathetic ganglia; sympatheticnociceptive
    afferent fi ber interaction is not reliant upon
    arachidonic acid cascade (i.e. Cox-2 mediated) products,
    and alpha adrenergic receptors are frequently upregulated
    on C-fi bers consequential to longitudinal sympathetic
    stimulation/sensitization.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q
  1. Sympathetically mediated pain
    A. Frequently produces temporally- dependent, variable
    sudo- and vaso- motor responses
    B. Involves a loss of A-beta mechanoreceptors from lamina
    II in the dorsal horn
    C. Is refl ective of increased number, frequency and duration
    of parasympathetic discharge
    D. Is explicitly dermatonal
    E. Characteristically does not involve thermal effects along
    the peripheral nerve territory
A
  1. Answer: A
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasiticity.
    Sympathetically mediated pain may initially produce
    vasodilatation and hyperhydrosis. However, as this pain
    persists, loss of vascular tone produces reactive
    vasoconstriction and prolong sympathetic actively alters
    sudomotor responses to produce a characteristic
    anhydrosis. Such thermal and sudomotor effects are not
    explicitly dermatonal but frequently involve the territory
    of multiple branches of affective peripheral nerve(s).
    Characteristically, parasympathetic modulation does not
    produce rebound or compensatory effects and the
    expression of alpha-adrenergic receptors on peripheral abeta
    mechanoreceptors may be an initiative mechanism
    that ultimately affects genomic-phenotypic expression and
    can enhance a-beta projections into laminae II of the spinal cord. Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q
  1. Long term, durable sympathetic activation
    A. Can induce expression of alpha-adrenergic receptors on
    sensitized C-nociceptive fi bers
    B. Produces adrenomedullary mediated pain modulation
    C. Causes desensitization of a-beta mechanoreceptors
    D. Produces a rightward shift in nociceptive threshold and
    fi ring patterns
    E. Is functional against neuropathic pain
A
  1. Answer: A
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasticity. Also Bonica’s
    Management of Pain, 3rd Ed: Ch4. Spinal mechanisms and
    modulation. Longitudinal sympathetic activation can
    induce denovo expression of alpha adrenergic receptors on
    (chemically pre-sensitized) nociceptive C-fi ber afferents
    and a-beta mechanoreceptors. Direct stimulation of these
    alpha-receptors by epinephrine released from sympathetic
    terminals can sensitize a-beta mechanoreceptors,produce a
    leftward shift in fi ring thresholds of a-beta and C-fi bers
    and induce both peripheral and ultimately central
    sensitization. Chronic sympathetic activation does not
    produce stress induced modulation of nociceptive or
    neuropathic pain.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q
  1. An increase in the output of a primary and/or secondorder
    pain afferent as a consequence of increased
    stimulation over a broader surface area of the affected
    region is known as:
    A. Temporal summation
    B. Allodynia
    C. Spatial summation
    D. Cross-sensitization
    E. All of the above
A
  1. Answer: C
    Explanation:
    Pain afferents are capable of summating output as a
    consequence of enhanced stimulation of numerous
    transductive receptors within their receptive fi eld(s). This
    is known as spatial summation; the greater the surface area
    stimulated,the greater the response output (amplitude and
    duration) of the respective nociceptive afferent.
    Temporal summation involves an increased number of
    noxious stimuli activating the receptive fi eld of a given
    nociceptor per unit time.
    Allodynia is the sensation of pain produced by nonnoxious
    stimuli as a result of nociceptor sensitization.
    Cross-sensitization involves the enhanced sensitivity of a
    nociceptor to distinct noxious stimuli following activation
    by another type of noxious stimuli. This process is due to
    enhanced transcription, translation, and expression of
    multiple membrane receptors that subserve transduction
    of distinct, specifi c noxious input.
    Source: Giordano J, Board Review 2005
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q
259. An absent ankle refl ex in a 35 year-old patient with acuteonset radicular pain would most likely involve which
nerve root?
A. L3
B. L4
C. L5
D. S1
E. S2
A
  1. Answer: D

Source: (Raj, Pain Review, 2nd Ed., page 68)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q
  1. The following is true regarding nitric oxide:
    A. It is preformed in the presynaptic terminal and stored in
    vesicles prior to release.
    B. It is considered a large molecule neurotransmitter and is
    actively transported across neural synapses.
    C. It is synthesized in the postsynaptic terminal by the enzyme
    cyclo-oxygenase.
    D. It is found only in the dorsal horn
    E. It is synthesized almost instantly in the presynaptic
    terminal and then diffuses into adjacent postsynaptic
    neurons.
A
  1. Answer: E
    Explanation:
    Reference:
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Peripheral Pain Mechanisms and Nociceptor Plasticity. pp.
    40-42.
    Nitrous oxide is a diffusible gas with numerous
    intracellular and extracellular effects. It is considered a
    small molecule neurotransmitter but it differs from other
    neurotransmitters in that it is not stored in vesicles.
    Instead it is synthesized almost instantly as needed within
    the presynaptic terminal by the action of the enzyme nitric
    oxide synthase. Once created it diffuses out of the presynaptic terminal within seconds and diffuses into
    adjacent neurons to affect numerous intracellular
    metabolic processes which modify neuronal excitability
    for seconds, minutes or longer. The actions of nitric oxide
    early in the infl ammatory response are largely protective
    with facilitation of blood fl ow, moderation of cell toxicity
    and scavenging of reactive oxygen molecules. Later in the
    infl ammatory cascade, nitric oxide becomes damaging and
    cytotoxic. Nitric oxide is thought to be involved in the
    development of neuropathic pain states. It is prevalent in
    various tissues including brain, gonads and dorsal horn.
    Source: Schultz D, Board Review 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q
261. The precentral gyrus and corticospinal tract are essential
for
A. Vision
B. Olfaction
C. Auditory identifi cation
D. Kinesthesia
E. Voluntary movement
A
  1. Answer: E
    Explanation:
    (Guyton, pp 638-640.) The precentral gyrus is the motor
    area of the cortex and the corticospinal tract is the
    pyramidal tract proper. These two structures are essential
    for voluntary movement. A supplementary motor area,
    whose function is still unknown, exists on the medial side
    of the hemisphere.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q
262. The middle cerebellar peduncle contains afferent fi bers
conveyed in the following tracts
A. Dorsal spinocerebellar
B. Ventral spinocerebellar
C. Tectocerebellar
D. Pontocerebellar
E. Vestibulocerebellar
A
  1. Answer: D
    Explanation:
    (Guyton, pp 648-650.) The middle cerebellar peduncle
    contains afferent fi bers conveyed in the pontocerebellar
    tract, which carries impulses from the motor area as well
    as other parts of the cerebellar cortex except the
    fl occulonodular lobe. The dorsal spinocerebellar and
    vestibulocerebellar afferent tracts enter the cerebellum via
    the inferior peduncle. The ventral spinocerebellar and
    tectocerebellar tracts enter via the superior cerebellar
    peduncle.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q
  1. At the neuromuscular junction, action potentials are
    coupled to neurotransmitter release by voltage-gated
    A. Ca2+ channels
    B. Na+ channels
    C. K+ channels
    D. Cl- channels
    E. Gap junctions between the presynaptic terminal and the
    muscle cell
A
  1. Answer: A
    Explanation:
    (Junqueira, 9/e, pp 157-159,186,194. Kandel, 4/e, pp
    43,175-177, 183, 210-211.)
    A. Ca2+ entry through specifi c channels results in fusion
    of acetylcholine-containing synaptic vesicles with the
    presynaptic membrane and ultimately the release of
    neurotransmitter. Neuromuscular, or myoneural,
    junctions represent the site at which end feet (boutons
    terminaux) come in close proximity to the surface of
    muscle cells. The arrangement is similar to that found in a
    synapse, and a neuromuscular junction can be considered
    the best-studied synapse.
    Ca2+ infl ux into the end feet may have a direct effect on
    phosphorylation of synapsin I, a vesicular membrane
    protein, which in its nonphosphorylated state blocks
    vesicle fusion with the presynaptic membrane.
    B, C, D. Na+,K+ , and Cl-voltage-gated channels are
    involved in the transmission of a nerve impulse but are
    not involved in the coupling of the action potential ( an
    electrical signal) to neurotransmitter release (a chemical
    alteration).
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q
264. Which of the following is absent from smooth muscle
cells?
A. Troponin
B. Calmodulin
C. Calcium
D. Myosin light chain kinase
E. Actin and tropomyosin interactions similar to skeletal
muscle
A
  1. Answer: A
    Explanation:
    (Alberts, 3/e, pp 856-857. Junqueira, 9/e,) Smooth muscle
    is the least specialized type of muscle and contains no
    troponin. The contractile process is similar to the actinmyosin
    interactions that occur in motility of nonmuscle
    cells. In the smooth muscle cell, actin and myosin are
    attached to intermediate fi laments at dense bodies in the
    sarcolemma and cytoplasm.Dense bodies contain a-actinin
    and, therefore, resemble the Z lines of skeletal muscle.
    Contraction causes cell shortening and a change in shape
    from elongate to globular. Contraction occurs by a sliding
    fi lament action analogous to the mechanism used by thick
    and thin fi laments in striated muscle. The connections to
    the plasma membrane allow all the smooth muscle cells in
    the same region to act as a functional unit. Sarcoplasmic
    reticulum is not as well developed as that in the striated
    muscles. There are no T tubules present; however,
    endocytic vesicles called caveolae are believed to function
    in a fashion similar to the T tubule system of skeletal
    muscle.
    When intracellular calcium levels increase, the calcium is
    bound to the calcium-binding protein calmodulin. Ca2+ -
    calmodulin is required and is bound to myosin light chain
    kinase to form a Ca2+-calmodulin-kinase complex. This
    complex catalyzes the phosphorylation of one of the two
    myosin light chains on the myosin heads. This
    phosphorylation allows the binding of actin to myosin. A
    specifi c phosphatase dephosphorylates the myosin light
    chain, which returns the actin and myosin to the inactive,
    resting state.The actin-tropomyosin interactions are
    similar in smooth and skeletal muscle.
    Smooth muscle cells (e.g., vascular smooth muscle cells)
    also differ from skeletal muscle cells in that they are
    capable of collagen, elastin, and proteoglycan synthesis,
    which is usually associated with fi broblasts.
    Source: Klein RM and McKenzie JC 2002.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q
  1. The principal action of the Quadratus Lumborum muscle
    is:
    A. Lateral fl exion of the lumbar spine
    B. Axial rotation of the lumbar spine
    C. Extension of the lumbar spine
    D. Fixation of the 12th rib during respiration
    E. Lateral rotation of the lumbar spine
A
  1. Answer: D
    Explanation:
    D. The principal action of the Quadratus Lumborum (QL)
    muscle is to fi x the 12th rib during respiration. It is a weak
    lateral fl exor of the lumbar spine.
    The QL is a fl at rectangular muscle that arises below
    from the iliolumbar ligament and the adjacent iliac crest.
    The insertion is into the lower border of the twelfth
    rib and the transverse processes of the upper four lumbar
    vertebrae.
    Patients usually present with low back pain.
    They have diffi culty turning over in bed, increased
    pain with standing upright. Coughing or sneezing may
    exacerbate their pain.
    Source: Chopra P, 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q
  1. Which of the following is an antiarrhythmic agent that
    has relatively few electrophysiologic effects on normal
    myocardial tissue but suppresses the arrhythmogenic
    tendencies of ischemic myocardial tissues?
    A. Propranolol
    B. Procainamide
    C. Quinidine
    D. Lidocaine
    E. Disopyramide
A
  1. Answer: D
    Explanation:
    Reference: Hardman, pp 865-867
    Lidocaine usually shortens the duration of the action
    potential and, thus, allows more time for recovery during
    diastole. It also blocks both activated and inactivated Na
    channels. This has the effect of minimizing the action of
    lidocaine on normal myocardial tissues as contrasted with
    depolarized ischemic tissues. Thus lidocaine is particularly
    suitable for arrhythmias arising during ischemic episodes
    such as myocardial infarction (MI).
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q
  1. The mechanism of the transcutaneous electrical nerve
    stimulation (TENS) in relieving pain is
    A. Direct electrical inhibition of type A-delta and C fi bers
    B. Depletion of neurotransmitter in nociceptors
    C. Hyperpolarization of spinothalamic tract neurons
    D. Activation of inhibitory neurons
    E. Distortion of nociceptors
A
  1. Answer: D
    Explanation:
    Transcutaneous nerve stimulation is low-intensity, mixedfrequency
    (2 and 100 Hz) electrical stimulation that is
    thought to produce analgesia by releasing endorphins.
    This technique is effective in treating nociceptive and
    deafferentation syndromes by a mechanism that is not
    reversed by naloxone. The mechanism is thought to be
    activation of inhibitory neurons and/or release of
    endogenous opiates.
    Source: Hall and Chantigan.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q
  1. The intensity of a signal that is transmitted to the brain
    can be increased by increasing the frequency of impulses
    traveling along a single fi ber. This is called
    A. spatial summation
    B. after-discharge
    C. temporal summation
    D. recruitment
    E. saltatory conduction
A
  1. Answer: C
    Explanation:
    The overall pattern of several impulses relaying similar
    information is termed a signal.
    A. The intensity of signal (such as pain) that is transmitted
    to the brain can be increased by increasing the number of
    parallel fi bers participating (spatial summation).
    B. After-discharge is production of output signals for
    prolonged periods by a single input stimulus.
    C. An intensity of signal (such as pain) that is transmitted
    to the brain can be increased by increasing the frequency
    of impulses traveling along a single fi ber is called temporal
    summation.
    D. The increase in the number of participating fi bers as the
    intensity of a signal increases is termed recruitment.
    E. Saltatory conduction is the process of successive
    excitation of nodes of Ranvier by an impulse that jumps
    between successive nodes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q
269. Acute intermittent porphyria is a contraindication of the
use of
A. Enfl urane
B. Nitrous oxide (N2O)
C. Ketamine
D. Diazepam
E. Thiopental
A
  1. Answer: E
    Explanation:
    Reference: Hardman, p 323.
    Induction of anesthesia by parenteral administration of
    thiopental sodium and other barbiturates is absolutely
    contraindicated in patients who have acute intermittent
    porphyria. These patients have a defect in regulation of
    delta-aminolevulinic acid synthetase; thus, administration
    of barbiturate that increases this enzyme may cause a
    dangerous increase in levels of porphyrins. Administration
    of a barbiturate would exacerbate the symptoms of
    gastrointestinal and neurologic disturbances, cause extensive demyelination of peripheral and cranial nerves,
    and could lead to death.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q
270. Of all the following endocrine glands, which one is not
subject to control by the brain?
A. Pancreatic islets
B. Pituitary
C. Parathyroid
D. Thyroid
E. Adrenal
A
  1. Answer: C
    Explanation:
    (Baum, pp 569-570.)
    B. Most glands receive either direct neural control from
    the brain or indirect control from hormones secreted by
    the hypothalamus.
    C. The parathyroids are notably free of brain control; in
    regulating calcium metabolism, they in turn are regulated
    by blood levels of calcium.
    D. Thyroid secretion is subject to hypothalamic control,
    whereas insulin secretion depends in part on adrenergic
    infl uence from the autonomic nervous system.
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q
  1. The fact that the pituitary secretion of endorphins is
    closely linked to the secretion of adrenocorticotropic
    hormone (ACTH) suggests that endorphins facilitate the
    ability to respond to
    A. Retarded growth
    B. Hypertension
    C. Stress
    D. Chronic Pain
    E. Tachycardia
A
  1. Answer: C
    Explanation:
    (Kandel, pp 286-296.)
    C. Under stressful conditions, the organism secretes
    endorphins and ACTH together. Proopiocortin is a
    common precursor.
    The close link between endorphins and ACTH suggests
    that they serve a mediation function for a closely related
    set of adaptation responses.
    They can facilitate one’s response to stress and at the
    same time help one to withstand pain and mobilize for
    coping activity to deal with the stressful challenge or
    threat. Almost every physical stress agent increases plasma
    levels of ß-endorphin as well as adrenocorticotropin and
    corticosterone.
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q
  1. The most common organic explanation for a sleep
    disturbance in a healthy person is:
    A. Disruption of normal circadian rhythms
    B. Accumulation of hepatic enzymes
    C. Overarousal and high activity during the day
    D. Suppressed REM sleep
    E. Misuse of hypnotics
A
  1. Answer: A
    Explanation:
    (Kandel, pp 936-947.)
    The two most frequent organic causes are disruption of
    normal circadian rhythms and the inevitable consequences
    of aging.
    A. The most common disruptions of normal circadian
    rhythms are related to travel (Jet lag) and behavioral
    changes in one’s normal daily routine, such as napping,
    irregular sleep hours and conditions, alteration in meal
    times, and unusual work schedules.
    The most common psychosocial cause of insomnia is
    emotional disturbance
    Normal aging is the next most common factor as it is
    more diffi cult to reset one’s biologic clock the older one
    gets. It has been estimated that most people over age 60
    sleep only about 5.5 h per day, and since stage 4 NREM sleep also declines with age, the lighter stages of NREM
    ` sleep allow the person to awaken more often, sometimes
    generating the worry that one cannot sleep or that one is
    not getting enough sleep.
    B. Accumulation of hepatic enzymes is a frequent side
    effect of prolonged use
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q
273. The theory of pain that states that psychological processes directly exert infl uence on the pain perception process is the
A. Gate control theory
B. Nociception theory
C. Specifi city theory
D. Polymodal nociceptor theory
E. Pattern theory
A
  1. Answer: A
    Explanation:
    A complex pathway allows opportunities for alteration
    and modulation of the incoming pain signals by other
    signals, including the inhibiting impulses that descend
    from the brain.
    A.The gate control theory proposes that there is a structure
    in the dorsal horn of the spinal cord that acts as a gate for
    increasing or decreasing nerve impulse fl ow from the
    peripheral fi bers to the central nervous system. This
    allows sensory input to be reviewed and modifi ed at the
    gate before it evokes pain. Sensory input is increased or
    decreased by the activity of large diameter fi bers (Aß
    fi bers), small diameter fi bers (Ad and C fi bers), and
    descending fi bers from the brain.
    Impulses from the large fi bers can close the gate, inhibiting
    transmission, while activity from the small fi bers can open
    the gate to enhance transmission.
    Efferent impulses from the brain provide further
    infl uence and the access route for the psychological
    processes of anxiety, depression, attention, and past
    experience to alter the gate and thus directly infl uence the
    pain perception process.
    When the output of the spinal cord T cells exceeds a
    critical threshold level, neuromechanisms are activated
    that are responsible for both pain perception and
    behavioral responses to the pain.
    B. Nociceptors are nerve endings that transmit pain.
    C. The specifi city theory states that there are specifi c
    sensory receptors for touch, warmth, and pain.
    D. Polymodal nociceptors are nerves that maximally
    respond to mechanical and temperature stimulation.
    E. The pattern theory states that pain sensations are the
    result of nerve impulse patterns being transmitted from
    and coded at the peripheral site.
    (Baum, pp 313-321.)
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q
274. A patient with ulcerative colitis is best treated with
A. Celecoxib
B. Naproxen
C. Sulfasalazine
D. Infl iximab
E. Penicillamine
A
  1. Answer: C
    Explanation:
    Reference: Katzung, pp 612, 1073.
    Sulfasalazine is a dervative of sulfapyridine and 5-
    aminosalicylic acid. It is not signifi cantly absorbed
    following oral administration. The 5-aminosalicyclic acid
    moiety is released by intestinal bacterial action.
    Slefasalazine is more effective in maintaining than causing
    remission in ulcerative colitis. Celocoxib (a selective
    cyclooxygenase inhibitor), infl iximab ( a chimeric
    monoclonal antibody), and penicillamine (an analogue of
    cysteine) have a role in the treatment of rheumatoid
    arthritis. Naproxen a nonselective cyclooxygenase
    inhibitor, is indicated for usual rheumatological
    indications.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q
  1. A patient presents with an acute onset of lateral upper
    arm pain. On physical exam there is a weakness on
    resisted shoulder external rotation and abduction, loss
    of sensation overlying a portion of the lateral aspect of
    the shoulder and proximal shoulder, and blunting of the
    biceps refl exes. Neck rotation and lateral fl exion worsens
    the arm pain. An MRI of the neck confi rms the presence
    of a paracentral disc protrusion at which level?
    A. C4-5
    B. C5-6
    C. C6-7
    D. C3-4
    E. C7-T1
A
  1. Answer: A

Source: (Raj, Pain Review 2nd Ed., page 62).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q
  1. A patient presents with an acute onset of pain extending
    down to the radial aspect of the arm and complaints of
    a ‘numb thumb’. On physical exam there is weakness
    elbow fl exion and supination, loss of sensation in the
    radial aspect of the forearm and the thumb. There is
    blunting of the brachioradialis refl ex. Neck rotation and
    lateral fl exion worsens the arm pain. An MRI of the neck
    confi rms the presence of a paracentral disc protrusion at
    which
    A. C4-5
    B. C5-6
    C. C6-7
    D. C3-4
    E. C7-T1
A
  1. Answer: B

Source: (Raj, Pain Review, 2nd Ed., page 62)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q
277. Seizures produced by local anesthetics appear to arise
from what area of the brain?
A. Thalamus
B. Geniculate bodies
C. Reticular activating system
D. Amygdala
E. None of the above
A
  1. Answer: D
    Source: Raj P, Pain medicine - A comprehensive Review -
    Second Edition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q
  1. A volunteer medical student takes part in a sleep
    laboratory experiment in which he is awakened repeatedly
    when his electroencephalogram (EEG) indicates that
    he has entered rapid-eye-movement (REM) sleep. This
    disruption of normal sleep is most likely to produce
    A. A rebound phenomenon of increased dreaming
    B. An increase in anxiety and irritability
    C. Acceleration of memory formation of emotionally toned
    words
    D. A decrement in intellectual function
    E. A temporary increase in nightmares
A
  1. Answer: A
    Explanation:
    (Kandel, pp 936-947.)
    Paradoxical sleep is a term given to REM sleep, which is
    considered paradoxical because its
    electroencephalographic pattern resembles that of the alert
    waking state. Dreaming occurs during REM sleep.
    A. When a person is repeatedly awakened during
    dreaming, a dream deprivation occurs and there is a
    rebound phenomenon of increased frequency and
    lengthening of dreaming when the person is permitted to
    sleep normally.
    B. The earlier studies suggested the presence of bizarre
    behavior, anxiety, irritability, and nightmares.
    However, more recent studies have found no such
    changes in humans even after 16 days of deprivation of
    dream sleep.
    C.Dream deprivation does not result in a major
    decrement in psychological or intellectual functions (as
    does sleep deprivation), but it does appear to retard the
    memory formation of emotionally toned words.
    Source: Ebert 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q
279. The substantia gelatinosa of the spinal cord is located in
A. Lamina I
B. Lamina II
C. Lamina IV
D. Lamina VII
E. Lamina IX
A
  1. Answer: B
    Explanation:
    The gray matter of the spinal cord is divided into the 10
    laminae of Rexed, which form a cytoarchitectonic map of
    this spinal cord that correlates well with synaptic
    connections and neurophysiological data. Laminae I, II,
    III, and IV encompass most of the dorsal horn, which receives primary sensory fi bers. Lamina I corresponds to
    the nucleus postmarginalis, Lamina II corresponds to the
    substantia gelatinosa and lamina III and IV correspond to
    the nucleus proprius dorsalis. All these nuclei integrate
    and modulate sensory information. They relay sensory
    information to higher centers like the cerebellum,
    thalamus, and brain stem. (Afi fi and Bergman, 66)
    Source: Neurology Examination and Board Review by Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q
  1. True statement about most A-delta and C fi bers
    A. are myelinated
    B. end as free nerve endings
    C. terminate in the deep dermis
    D. end as specifi c nociceptive receptors
    E. terminate in specialized structures
A
  1. Answer: B
    Explanation:
    A. Most A-delta and C fi bers are non-myelinated.
    B. Most A-delta and C fi bers end as free nerve endings.
    C. A-delta fi bers terminate in the epidermis, while C
    fi bers may end in the superfi cial dermis.
    D. The transduction of noxious stimulation occurs in the
    free nerve ending.
    E. They do not terminate in specialized structures.
    Source: Kahn and Desio
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q
281. Intradiscal pressure increases with
A. Standing in fl exion
B. Coughing
C. Sneezing
D. Over night
E. All of the above
A
  1. Answer: E

Source: Rozen. Pain Practice: SEP 2001

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q
282. In a hypertensive patient who is taking insulin to treat
diabetes, which of the following drugs is to be used with
extra caution and advice to the patient?
A. Hydralazine
B. Prazosin
C. Guanethidine
D. Propranolol
E. Methyldopa
A
  1. Answer: D
    Explanation:
    Reference: Hardman, pp 855-856.
    Propranolol, as well as other nonselective beta blockers,
    tends to slow the rate of recovery in a hypoglycemic attack
    caused by insulin. Beta blockers also mask the symptoms
    of hypoglycemia and may actually cause hypertension
    because of the increased plasma epinephrine in the
    presence of a vascular beta2 blockade.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q
  1. If quinidine and digoxin are administered concurrently,
    which of the following effects does quinidine have on
    digoxin?
    A. The absorption of digoxin from the GI tract is decreased
    B. The metabolism of digoxin is prevented
    C. The concentration of digoxin in the plasma is increased
    D. The effect of digoxin on the AV node is antagonized
    E. The ability of digoxin to inhibit the Na+ K+ -stimulated
    ATPase is reduced
A
  1. Answer: C
    Explanation:
    Reference: Hardman, pp 870-871.
    Quinidine is often given in conjunction with digitalis. It
    has been found by pharmacokinetic studies that this
    combination results in quinidine’s replacing digitalis in
    tissue binding sites (mainly muscle), thus raising the
    blood level of digitalis and decresing its volume of
    distribution. A mechanism by which quinidine interferes
    with the renal excretion of digitalis has also been
    proposed.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q
  1. Which of the following extraocular muscles is innervated
    by a nucleus located on the contralateral side?
    A. Superior rectus
    B. Inferior rectus
    C. Medial rectus
    D. Lateral rectus
    E. Inferior oblique
A
  1. Answer: A
    Explanation:
    General somatic efferent fi bers of the oculomotor nerve
    arise from the oculomotor nucleus situated near the
    midline of the midbrain at the level of the superior
    colliculus. This nucleus is formed by subnuclei for each of
    the extraocular muscles. The superior rectus muscle
    receives innervation from neurons in the contralateral subnucleus. The levator palpebral superioris muscle
    receives innervation from a medial subnucleus. The
    inferior rectus, medial rectus, and inferior oblique muscles
    receive innervation from ipsilateral subnuclei. (Burt,
    403-406)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q
285. The most likely neurotransmitter for cerebella climbing
fi bers is
A. Acetylcholine
B. Glutamate
C. Aspartate
D. Dopamine
E. Glycine
A
  1. Answer: C
    Explanation:
    Climbing fi bers are axons of neurons originating from the
    contralateral inferior olivary nucleus that project to all
    areas of the cerebellar cortex. Climbing fi bers are
    excitatory. Aspartate is the most likely transmitter for
    these fi bers. Each single climbing fi ber establishes 1000
    to 2000 synaptic contacts with its Purkinje cell. When the
    climbing fi bers fi re, there is a massive synchronous
    depolarization of Purkinje cells, which activates Ca++
    channels in the dendritic membrane. The major source of
    climbing fi bers in the cerebellum is the inferior olive.
    Degeneration of the inferior olive (seen in olivocerebellar
    atrophy) induces a drop in aspartate level in the
    cerebrospinal fl uid. (Afi fi and Bergman, 313-314)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q
  1. Which of the following is the best advantage of atypical
    antipsychotic medications over traditional antipsychotic medications?
    A. Purely adrenergic antagonists
    B. More effective for positive symptoms
    C. Lower risk for extrapyramidal side effects
    D. More effective for mood disorders with psychotic features
    E. Increased effi cacy for behavioral symptoms with dementias
A
286. Answer: C
Explanation:
Older antipsychotics are being phased out because of the
risk of EPS
Source: Boswell MV, Board Review 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q
  1. Vertigo, inability to perceive termination of movement,
    and diffi culty in sitting or standing without visual clues
    are some of the toxic reactions that are likely to occur in
    about 75% of patients treated with
    A. Penicillin G
    B. Doxycycline
    C. Amphotericin B
    D. Streptomycin
    E. INH
A
  1. Answer: D
    Explanation:
    Reference: Hardman, pp 11110-1113.
    Streptomycin and other aminoglycosides can elicit toxic
    reactions involving both the vestibular and auditory
    branches of the eighth cranial nerve. Patients receiving
    an aminoglycoside should be monitored frequently for any
    hearing impairment owing to the irreversible deafness that
    may result from its prolonged use.None of the other
    agents listed in the question adversely affect the function
    of the eighth cranial nerve.
    Source: Stern-2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q
288. The cerebellar cortex contains all of the following types
of cells EXCEPT
A. Pyramidal cells
B. Purkinje cells
C. Granule cells
D. Golgi cells
E. Basket cells
A
  1. Answer: A
    Explanation:
    The cerebellar cortex contains three laminated cellular
    layers: the outermost molecular cell layer, a sheet of single
    large neurons; the Purkinje cell layer; and a deeper
    granular cell layer. These layers contain six types of
    neurons; basket, satellite, Purkinje, Golgi, granule cells,
    and the relatively rare Legato cells. Pyramidal cells are the
    most abundant cells of the cerebral cortex neuron types,
    are not found in the cerebellum, and are the most
    characteristic of the cerebral cortex. (Afi fi and Bergman,
    308-310)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q
289. Which of the following is an H2-receptor antagonist?
A. Sumatriptan
B. Cyproheptadine
C. Ondansetron
D. Cimetidine
E. Fluoxetine
A
  1. Answer: D
    Explanation:
    Reference: Katzung, p 275.
    Cimetidine is an H2 antagonist that decreases gastric acid
    secretion. Sumatriptan is a 5-HT1D serotonin agonist.
    Cyproheptadine acts as a histamine and serotonin
    antagonist. Ondansetron is a serotonin antagonist.
    Fluoxetine is an antidepressant agent that selectively
    inhibits serotonin reuptake.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q
  1. Which of the following is true about the trigeminal nerve
    nuclei?
    A. The trigeminal nerve has two sensory nuclei
    B. Pain and temperature are carried predominantly by the
    spinal nucleus of the trigeminal nerve
    C. Most small fi bers efferent of the spinal tract of the trigeminal
    nerve end in the main sensory nucleus of that
    nerve
    D. The motor nucleus of the trigeminal nerve innervates
    the muscle of mastication via its maxillary division
    E. The motor nucleus of the trigeminal nerve contains only
    alpha motor neurons
A
  1. Answer: B
    Explanation:
    The trigeminal nerve has three sensory nuclei: The spinal
    nucleus, the main sensory nucleus and the mesencephalic
    nucleus. The spinal nucleus of the trigeminal nerve is a
    long column of neurons extending from the point of entry
    of the trigeminal nerve to the upper cervical spinal cord.
    Itis divided into three parts: The oral part, responsible for
    tactile sensation from the oral mucosa; the interpolar part,
    receiving efferents for dental pain; and the caudal part,
    receiving pain and temperature sensations from the face.
    Most of the small efferent fi bers of the spinal tract of the
    trigeminal nerve terminate in the spinal nucleus. Most of
    the efferent large fi bers that originate from the trigeminal
    ganglion end in the main sensory nucleus and are
    responsible for the transmission of discriminative touch.
    The mesencephalic nucleus is located at the rostral pons.
    It receives efferent fi bers conveying kinesthesia and
    pressure from the teeth, periodontium, hard palate,
    joint capsules, the stretch receptors from the muscles of
    mastication.It sends efferent fi bers to the cerebellum, the
    thalamus, the motor nuclei of the brain stem,and the
    reticular formation.
    The motor nucleus of the trigeminal nerve provides
    somatic visceral efferents that innervate the muscles of
    mastication via the mandibular division and contains ?
    and ? motor neurons. (Afi fi and Bergman, 171-175)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q
  1. The source of noradrenergic projection to the cerebellum
    is the
    A. Dorsomedial nucleus of the hypothalamus
    B. Locus ceruleus
    C. Raphe nucleus
    D. Thalamus
    E. Inferior olivary nucleus
A
  1. Answer: B
    Explanation:
    The monoaminergic projections to the cerebellum
    originate from the pontine raphe nuclei,the locus ceruleus,
    and the hypothalamus. The raphe nuclei are the source of
    serotoninergic projections to both the granular and
    molecular layers. The locus ceruleus is the source of
    noradrenergic projection to the three layers of the
    cerebellar cortex. The dorsomedial, dorsal, and lateral
    areas of the hypothalamus are the sources of histaminergic
    projections to all three layers of the cerebellar cortex.
    (Afi fi and Bergman, 322)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q
292. Which of the following sensory pathways does NOT
project to the thalamus ?
A. Visual sensation pathway
B. Auditory sensation pathway
C. Vibration sensation pathway
D. Olfactory sensation pathway
E. Temperature sensation pathway
A
  1. Answer: D
    Explanation:
    The olfactory pathway is the only sensory pathway that
    does not project to the thalamus. The olfactory nerve penetrates the cribriform plate of the ethmoid bone and
    enters the olfactory bulb to synapse with the second-order
    neurons: mitral and tufted cells. The axons of the secondorder
    neurons course posteriorly as the olfactory tract in
    the orbital surfaces of the frontal lobe and project to the
    primary olfactory cortex in the temporal lobe. (Parent,
    748-754)
    SOURCE: Souayah, N, and Khella S; Neurology
    Examination & Board Review; McGraw-Hill, New York.
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q
  1. Presynaptic inhibition in the central nervous system
    affects the fi ring rate of alpha motoneurons by
    A. Increasing the chloride permeability of the presynaptic
    nerve ending
    B. Decreasing the potassium permeability of the alpha
    motoneuron
    C. Decreasing the frequency of action potentials by the
    presynaptic nerve ending
    D. Increasing (hyperpolarizing) the membrane potential of
    the alpha motoneuron
    E. Increasing the amount of the neurotransmitter released
    by the presynapticnerve ending
A
  1. Answer: A
    Explanation:
    (Guyton, p 516-517, 523.) Presynaptic inhibition caused
    by interneurons that secrete a transmitter which increases
    the Cl- conductance of the presynaptic nerve ending. The
    increase in Cl- conductance causes a partial depolarization
    of the presynaptic nerve ending and a decrease in the
    magnitude of the action potential in the presynaptic nerve
    ending. Because the amount of mediator released at the
    synapse is related to the magnitude of the action potential,
    less transmitter is released and the fi ring rate of the
    postsynaptic alpha motoneuron is decreased. Presynaptic
    inhibition does not change the membrane potential of the
    alpha motoneuron, and therefore the membrane potential
    of the alpha motoneuron is not affected.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q
294. The positions associated with the greatest amount of load
on the lumbar intervertebral disks is
A. Lying supine
B. Sitting, bending over
C. Sitting with back straight
D. Standing, fl exed at the waist
E. Standing upright
A
  1. Answer: B
    Explanation:
    A. The load decreases signifi cantly in supine position.
    B. With the patient sitting with the back unsupported or
    sitting and bending over, the load shows greater increase.
    C. In the sitting position with the back straight, the load is
    increased 40 percent above relaxed standing.
    D. With the subject standing and bending, the load
    increases 50 percent.
    E. Upright standing is equal to 100 percent of the relative
    load.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q
  1. A 55-year old morbidly obese female arrives at the clinic
    complaining of decreased sensation over the anterior
    thigh between the inguinal ligament and knee joint. She
    states that she has loss of sensation in the anterior thigh
    from the inguinal ligament to the knee and is generalized
    medial to lateral. The patellar, quadriceps refl ex is
    generally intact. Nerves that most likely represent this
    innervation include:
    A. L1
    B. L2
    C. L3
    D. L4
    E. L5
A
  1. Answer: C
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT p.
    250.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q
296. The major factor limiting oral bioavailability of morphine
is
A. Gastric emptying time
B. Intestinal enzymes
C. Liver metabolism
D. Hydrophilicity
E. Bile secretion
A
  1. Answer: C
    Explanation:
    First pass metabolism is the main factor that reduces the
    amount of morphine that reaches the systemic circulation.
    Source: Boswell MV, Board Review 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q
297. The substantia gelatinosa resides in the laminar segment
of the spinal cord
A. X
B. VII
C. V
D. II
E. I
A
  1. Answer: D
    Explanation:
    Rexed divided the spinal gray into ten laminae.
    Laminae I through VI make up the dorsal horn.
    Laminae VII through IX make up the ventral horn.
    Lamina X is composed of a column of cells clustered
    around the central canal of the cord.
    Lamina I is the marginal layer, lamina II is the substantia
    gelatinosa, and laminae II through V make
    up the nucleus propius (magnocellular layer).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q
  1. The risk of acute dystonic reactions from antipsychotic
    agents is greatest for which of the following?
    A. Older women
    B. Previous dystonic reaction
    C. Administration by the oral route
    D. Using lower doses of medication
    E. Use of atypical antipsychotic medications
A
  1. Answer: B
    Explanation:
    B. Previous dystonic reaction is a risk factor for acute
    dystonic reaction, as are male sex, younger age, higher
    doses of drugs and parenteral administration.
    Atypical agents have less risk.
    Source: Boswell MV, Board Review 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q
  1. The nucleus raphe Magnus is highly involved with the
    neural processing of what type of painful afferent input?
    A. Mechanical
    B. Thermal
    C. Mixed
    D. All of the above
    E. None of the above
A
  1. Answer: B

Source: Giordano J, Board Review 2003

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q
  1. A 60-year-old male complains of severe headaches,
    nausea, dizziness and a diminution in vision. He has
    a decrease in oxygen (O2)-carrying capacity without
    a change in the Po2 of arterial blood. Which of the
    following might account for these fi ndings?
    A. Sulfur dioxide
    B. Ozone
    C. Nitrogen dioxide
    D. Carbon monoxide (CO)
    E. Methane
A
  1. Answer: D
    Explanation:
    Reference: Hardman, pp 1676-1678. Katzung, pp 990- 991.
    Carbon monoxide is a common cause of accidental and
    suicidal poisoning. Its affi nity for hemoglobin is 250 times
    greater than that of O2. It therefore binds to hemoglobin
    and reduces the O2 – carrying capacity of blood. The
    symptoms of poisoning are due to tissue hypoxia; they
    progress from headache and fatigue to confusion, syncope,
    tachycardia, coma, convulsions, shock, respiratory
    depression, and cardiovascular collapse. Carboxyhemoglobin
    levels below 15% rarely produce symptoms;
    above 40%, symptoms become severe. Treatment include
    establishment of an airway, supportive therapy, and
    administration of 100% O2 . Sulfur dioxide, ozone, and
    nitrogen dioxide are mucous membrane and respiratory
    irritants. Methane is a simple asphyxiant.
    Source: Stern - 2004
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q
301. The Achilles tendon is innervated by:
A. L4
B. L5
C. S1
D. S2
E. L3
A
  1. Answer: C
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT p.
    227.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q
  1. Which is not a putative Neurochemical mediator at
    synaptic connections within the dorsal horn?
    A. Deltorphin
    B. Glutamate
    C. Glycine
    D. Enkephalin
    E. Serotonin
A
  1. Answer: A

Source: Giordano J, Board Review 2003

98
Q
  1. Which of the following is true regarding phantom limb
    sensations?
    A. Body parts that are sparsely innervated are most commonly
    represented
    B. Phantom sensations are unpleasant with burning and
    jabbing
    C. The incidence of phantom sensations decreases with
    age.
    D. The amputated limb phantom may feel shortened
    E. Phantom limb sensations require peripheral input
A
  1. Answer: D
    Explanation:
    Phantom limb sensation is an almost universal occurrence
    at some time during the fi rst month following surgery.
    A. The strongest sensations come from body parts with the
    highest brain cortical representation, such as the fi ngers
    and toes. These highly innervated parts are also the areas
    of most persistent phantom limb sensation.
    B. Phantom sensations are either normal in character or as pleasant warmth and tingling. These are not painful.
    C. The incidence of phantom limb sensation increases
    with the age of the amputee. In children who have
    amputation before 2 years of age, the incidence of
    phantom limb sensation is 20%; the incidence of phantom
    limb sensation is nearly 100% when amputation occurs
    after 8 years of age.
    D. The phantom limb may undergo the phenomenon
    known as telescoping, in which the patient loses sensations
    from the mid portion of the limb, with subsequent
    shortening of the phantom. Telescoping is most common
    in the upper extremity. During telescoping, the last body
    parts to disappear are those with the highest
    representation in the cortex, such as the thumb, index
    fi nger, and big toe.
    Only painless phantoms undergo telescoping, and
    lengthening of the phantom may occur if the pain returns.
    Thus, patients may feel that the amputated phantom limb
    shortened.
    E. Phantom limb sensations do not appear to require
    peripheral nervous system input. Phantom limb
    sensations may be an attempt to preserve the self image
    and minimize distortion of the self image or may be a
    permanent inherited neural memory of postural patterns.
    Reference: Hord and Shannon. Chapter 16. Phantom Pain.
    In: Practical Management of Pain, 3rd Edition.
    Raj et al. Mosby, 2000, page 212-213.
99
Q
  1. A 30-year-old woman has diffi culty talking 15 minutes
    after initiation of interscalene block for closed reduction
    of a dislocated shoulder. The most likely cause is
    A. Cervical Sympathetic Block
    B. Delayed systemic toxic reaction
    C. Phrenic nerve paralysis
    D. Pneumothorax
    E. Recurrent laryngeal nerve block
A
  1. Answer: E
100
Q
305. The visceral afferent fibers of the heart are transmitted
through what nerves?
A. Vagus
B. Middle cervical ganglia
C. Thoracic cardiac nerves
D. Thoracic ganglia 3-6
E. Inferior cervical ganglia
A
  1. Answer: A
    Explanation:
    Ref: Raj. Chapter 43. Thoracoabdominal Pain. In:
    Practical Management of Pain. 3rd Edition. Raj et al,
    Mosby, 2000. page 618.
    Source: Day MR, Board Review 2003
101
Q
306. Thalamocortical afferents have their main terminals in
the cerebral cortex layer number
A. I
B. II
C. III
D. IV
E. V
A
  1. Answer: D
    Explanation:
    Layer IV of the cerebral cortex, the internal granular layer,
    is the principal receiving station of the cortex. The input
    from the modality specifi c thalamic nuclei projects mainly
    onto neurons in lamina IV, with some projections on
    laminae III and IV. The nonspecifi c thalamocortical input
    originating from nonspecifi c thalamic nuclei projects
    diffusely on all laminae and establishes mostly
    axodendritic types of synapses. (Afi fi and Bergman, 340-
    343; Burt 451-452)
    Source: Neurology Examination and Board Review By
    Nizar Souayah, MD and Sami Khella, MD
102
Q
  1. In which one of the following sensory systems does
    stimulation cause the receptor cell to hyperpolarize?
    A. Vision
    B. Hearing
    C. Taste
    D. Touch
    E. Smell
A
  1. Answer: A
    Explanation:
    (Guyton, pp 581-582.) The visual receptor cells, the rods
    and cones, are depolarized in their nonstimulated state.
    When exposed to light, they hyperpolarize.Light causes the
    rods and cones to hyperpolarize by activating a G protein
    called transducin, which leads to the closing of Na+ channels. Auditory receptors are depolarized by the fl ow of
    K+ into the hair cells. Touch receptors are activated by
    opening channels through which both Na+ and K+ can
    fl ow. Depolarization is caused by the inward fl ow of Na+.
    Smell and taste receptors are activated by G-protein
    mediated mechanisms, some of which cause the receptor
    cell to depolarize; other G proteins cause the release of
    synaptic transmitter without any change in membrane
    potential.
103
Q
308. The central opioid peptides leu- and met-enkephalin
are the principal endogenous ligands at which opioid
receptor(s)?
A. Delta and kappa
B. Spinal kappa only
C. Mu and delta
D. Mu and supraspinal kappa
E. kappa and Mu
A
  1. Answer: C

Source: Giordano J, Board Review 2003

104
Q
  1. Which of the following is true regarding drug
    absorption?
    A. Specialized transport systems are usually required
    B. Passive diffusion is most common mechanism
    C. Drug absorption usually is energy-dependent
    D. Increased lipid solubility reduces uptake
    E. Ionic charge facilitated drug uptake
A
  1. Answer: B
    Explanation:
    Most uptake is by passive diffusion
    Source: Boswell MV, Board Review 2004
105
Q
  1. The adrenal cortex infl uences the secretion of the adrenal medulla by
    A. Secretion of aldosterone into the intra-adrenal circulation
    B. Secretion of glucocorticoids into the intra-adrenal circulation
    C. Autonomic neural connections
    D. Secretion of monoamine oxidase into the portal circulation
    E. Secretion of androgens into the intrarenal circulation
A
  1. Answer: B
    Explanation:
    (Braunwald, 15/e, pp 439–440, 2088. Junqueira, 9/e, pp
    387-389.) Metabolism in the adrenal medulla is regulated
    by glucocorticoids because they induce the enzyme
    phenylethanolamine-N-methyltransferase, which catalyzes
    the methylation of norepinephrine to epinephrine.Most of
    the blood supply entering the medulla passes through the
    cortex. Glucocorticoids synthesized in the zona fasciculata
    of the adrenal are released into the sinusoids and enter the
    medulla. The adrenal gland is not usually considered a
    classic portal system although there are similarities.
    Monoamine oxidase is a mitochondrial enzyme that
    regulates the storage of catecholamines in peripheral
    sympathetic nerve endings.
    The adrenal gland functions as two separate glands. The
    adrenal cortex is derived from mesoderm and the adrenal
    medulla from neural crest. The blood supply to the adrenal
    is derived from three adrenal arteries: (1) the superior
    adrenal (suprarenal) from the inferior phrenic, (2) the
    middle adrenal from the aorta, and (3) the inferior adrenal
    from the renal artery.
    Source: Klein RM and McKenzie JC 2002.
106
Q
311. The hypothalamic nuclei is responsible for controlling the normal circadian rhythm is:
A. Paraventricular nucleus
B. Ventromedial nucleus
C. Arcuate nucleus
D. Lateral nucleus
E. Suprachiasmatic nucleus
A
  1. Answer: E
    Explanation:
    (Rhoades, pp 130-132.) A variety of physiological
    functions, such as alertness (the sleep-wake cycle), body
    temperature, and secretion of hormones, exhibits cyclic
    activity that varies over a 24-h period of time. These
    variations in activity are called circadian rhythms and are
    controlled by the suprachiasmatic nucleus of the
    hypothalamus. The paraventricular nucleus secretes
    oxytocin and vasopressin, the ventromedial and lateral
    nuclei control food intake, and the arcuate nucleus secretes
    gonadotropin-releasing hormone.
107
Q
312. The hormone with the greatest role in aggression is
A. Thyroxine
B. Testosterone
C. Estrogen
D. Progesterone
E. Aldosterone
A
  1. Answer: B
    Explanation:
    Carlson, pp 352-359.
    B. Testosterone administered postpubertally to castrated rats can restore aggressiveness to almost normal levels.
    Similarly, neonatal female mice develop masculine
    aggressive behavior on receiving androgens. Androgens
    also promote aggression in humans.
    C. Boys are more aggressive than girls at ages 3 to 10, as
    has been demonstrated in studies of children.
    Source: Ebert 2004
108
Q
  1. A patient presents with an acute onset of dorsal forearm
    pain. On physical exam there is a weakness of elbow
    extension and loss of the triceps refl ex. Neck rotation and
    lateral fl exion worsens the arm pain. An MRI of the neck
    confi rms the presence of a paracentral disc protrusion at
    which level?
    A. C4-5
    B. C5-6
    C. C6-7
    D. C3-4
    E. C7-T1
A
  1. Answer: C

Source: (Raj, Pain Review, 2nd Ed., page 62)

109
Q
314. The afferent limb of the oculocardiac refl ex is by way of the following.
A. Facial
B. Optic
C. Ophthalmic
D. Vagus
E. Ciliary
A
  1. Answer: C
    Explanation:
    The oculocardiac refl ex is defi ned as a slowing of the pulse
    in response to traction on the extraocular muscles or from
    pressure on the eye.
    C. The afferent arc is by way of the ophthalmic branch of
    the trigeminal nerve. Impulses travel through the reticular
    network to the visceral motor nuclei of the vagus nerve,
    which is the efferent limb of the refl ex to the heart.
110
Q
315. Hypotension, bradycardia, respiratory depression, and
muscle weakness, all unresponsive to atropine and
neostigmine, would most likely be due to
A. Diazoxide
B. Isofl uorphate
C. Tubocurarine
D. Nicotine
E. Pilocarpine
A
  1. Answer: D
    Explanation:
    Reference: Hardman, pp 192-193.
    Nicotine is a depolarizing ganglionic blocking agent that
    initially stimulates and then blocks nicotinic muscular
    (NM) (skeletal muscle) and nicotinic neural (NN)
    (parasympathetic ganglia) cholinergic receptors. Blockade
    of the sympathetic division of the autonomic nervous
    system (ANS) results in arteriolar vasodilation,
    bradycardia, and hypotension. Blockade at the
    neuromuscular junction leads to muscle weakness and
    respiratory depression caused by interference with the
    function of the diaphragm and intercostal muscles.
    Atropine, a muscarinic receptor blocker, would be an
    effective antagonist, as would neostigmine, a
    cholinesterase inhibitor. Pilocarpine and isofl uorphate are
    cholinomimetics and can be antagonized by atropine; the
    effects of tubocurarine can be inhibited by neostigmine.
    Diazoxide, a vasodilator, would cause tachycardia, rather
    than bradycardia.
    Source: Stern 2004
111
Q
316. Which of the following ligands activate G-protein coupled receptors?
A. Acetylcholine
B. Morphine
C. Insulin
D. Cortisol
E. GABA
A
  1. Answer: B
    Explanation:
    Acetylcholine and GABA bind ionic channel receptors,
    insulin binds Tyrosine Kinase receptors and cortisol binds
    nuclear receptors.
    Source: Boswell MV, Board Review 2004
112
Q
  1. The cells of the adrenal medulla are homologous to
    A. postganglionic parasympathetic neurons
    B. preganglionic sympathetic neurons
    C. cholinergic interneurons
    D. preganglionic parasympathetic neurons
    E. postganglionic sympathetic neurons
A
  1. Answer: E
    Explanation:
    Norepinephrine is the neurotransmitter found in
    postganglionic sympathetic (adrenergic) nerve endings.
    The cells of the adrenal medulla are homologous to
    postganglionic sympathetic neurons and contain both
    epinephrine (80 percent) and norepinephrine (20
    percent).
    Source: Kahn and Desio
113
Q
318. The sympathetic response in a “fight or flight” reaction causes a decrease in
A. The arterial blood pressure
B. The diameter of the pupil
C. The resistance of the airways
D. The heart rate
E. The blood glucose concentration
A
  1. Answer: C
    Explanation:
    (Guyton, 9/e, pp 705-707.) The entire sympathetic nervous
    system is activated when a person is frightened, preparing
    the individual for fl ight or to fi ght. As part of this
    preparation, the smooth muscle of the airways is relaxed,
    increasing the airway diameter, making it easier for the
    person to breathe. At the same time, heart rate and cardiac
    output are increased, causing a rise in blood pressure, and
    blood glucose concentrations are increased, making fuel
    available for whatever choice is made.
114
Q
319. When testing sensation in the thoracic region, the
dermatomes that would most likely approximate nipple
level would be
A. T3
B. T4
C. T6
D. T5
E. T7
A
  1. Answer: B
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT
115
Q
320. The extensor hallucis longus deep is innervated by the branch of the peroneal nerve from the following nerve:
A. L4
B. L3
C. L2
D. L5
E. S1
A
  1. Answer: D
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT p.
    227.
116
Q
  1. True statements regarding the Babinski Test include:
    A. In a negative reaction the toes do not move or bunch
    up.
    B. In a positive reaction the great toe extends while the
    other separate.
    C. A positive Babinski refl ex indicates an upper motor
    neuron lesion.
    D. A positive Babinski s normal in a newborn.
    E. All of the above
A
  1. Answer: E
    Source: Hoppenfeld, Stanley, Physical Examination of the
    Spine and Extremities, Appleton-Centry-Cross/Norwalk,
    CT p.256
117
Q
322. Free nerve endings contain receptors that encode the
sensation of
A. Fine touch
B. Vibration
C. Pressure
D. Temperature
E. Muscle length
A
  1. Answer: D
    Explanation:
    (Guyton, pp 561-563.) Free nerve endings contain
    receptors for temperature, pain, and touch. However, fi ne
    touch, pressure, and vibration are detected by nerve
    endings contained within specialized capsules that
    transmit the stimulus to the sensory receptors. Muscle
    length is encoded by the primary nerve endings of Ia fi bers
    which are located on intrafusal fi bers within the muscle
    spindle.
118
Q
323. A dopamine receptor agonist that is useful in the therapy of Parkinson’s disease is
A. Selegiline
B. Bromocriptine
C. Apomorphine
D. Amantidine
E. Belladonna
A
  1. Answer: B
    Explanation:
    Reference: Katzung, pp 468-469:
    A. Selegiline is an MAO-B inhibitor.
    B. Bromocriptine mimics the action of dopamine in the
    brain but is not as readily metabolized. It is especially
    useful in parkinsonism that is unresponsive to L-dopa.
    C. Apomorphine is also a dopamine receptor agonist, but
    its side effects preclude its use for this purpose.
    D. Amantadine is an antiviral agent that probably affects
    the synthesis or uptake of dopamine.
    E. Atropine is belladonna preparation.
    Source: Stern - 2004
119
Q
  1. What is the cause of neuroleptic malignant syndrome?
    A. Inhibition of serotonin reuptake in the CNS
    B. Blockade of central dopamine receptors
    C. Central dopamine receptor hypersensitivity to neuroleptics
    D. Depletion of synaptic dopamine stores in the CNS
    E. Anaphylactic reaction to a neuroleptic medication
A
  1. Answer: B
    Explanation:
    Neuroleptic malignant syndrome is an uncommon but
    potentially fatal idiosyncratic reaction characterized by the
    development of altered consciousness, hyperthermia,
    autonomic dysfunction, and muscular rigidity on exposure
    to neuroleptic (and probably other psychotropic)
    medications. The pathophysiology of neuroleptic
    malignant syndrome (NMS) is poorly understood. The
    postulated mechanism involves blockade of central
    dopamine receptors in the basal ganglia,the hypothalamus,
    and peripherally in postganglionic sympathetic neurons
    and smooth muscle
    Source: Laxmaiah Manchikanti, MD
120
Q
  1. A 27-year-old male has sprained his ankle, which is swollen
    and painful, while skiing. X-ray examination is negative
    except for the appearance of swelling. A nonsteroidal
    anti-infl ammatroy drug (NSAID) is administered. Which
    of the following would be decreased?
    A. Histamine
    B. Cortisol
    C. Bradykinin
    D. Prostacyclin
    E. Uric acid
A
  1. Answer: D
    Explanation:
    Reference: Hardman, p 617. Katzung, p 318.
    Most NSAIDs inhibit both cyclooxygenase I and II,
    resulting in decreased synthesis of prostaglandins,
    prostacyclins, and thromboxanes.
    Source: Stern - 2004
121
Q
326. The actin-rich cell cortex is involved in the following cell functions
A. Cytokinesis
B. Chromosomal movements
C. Bidirectional transport of vesicles
D. Fast axoplasmic transport
E. Ciliary movement
A
  1. Answer: A
    Explanation:
    (Alberts, 3/e, pp 813-814, 834.) The cell cortex is an area
    of the cell immediately underneath the plasma membrane
    and is rich in actin, which is required for cytokinesis. This
    region is important in maintaining the mechanical
    strength of the cytoplasm of the cell. It is also essential for
    cellular functions that require surface motility. These
    functions include phagocytosis, cytokinesis, and cell
    locomotion. Although movement of vesicles along
    fi laments is regulated by minimyosins (myosin 1),
    movement of vesicles and organelles is predominantly a
    function of microtubules under the infl uence of the
    unidirectional motors kinesin and dynein. The movements
    of cilia and fl agella are driven by dynein and chromosomal
    movements occur through microtubular kinetics.
    Source: Klein RM and McKenzie JC 2002.
122
Q
  1. Correct statements regarding rapid eye movement
    (REM) sleep include which of the following?
    A. It is the fi rst state of sleep entered when a person falls
    asleep
    B. It is accomplished by loss of skeletal muscle tone
    C. It is characterized by a slow but steady heart rate
    D. It occurs more often in adults than in children
    E. It lasts longer than periods of slow-wave sleep
A
  1. Answer: B
    Explanation:
    (Guyton, pp 689-691.) In a normal sleep cycle, a person
    passes through the four stages of slow-wave sleep before
    entering REM sleep. In narcolepsy, a person may pass
    directly from the waking state to REM sleep. REM sleep is
    characterized by irregular heart beats and respiration and
    by periods of atonia (loss of muscle tone). It is also the
    state of sleep in which dreaming occurs.
123
Q
  1. The pain produced by ischemia is poorly localized and
    throbbing while pain from a needle stick is well localized
    and sharp. Which of the following comparisons of
    ischemic and needle stick pain is correct?
    A. Ischemic pain sensory fi bers are classifi ed as A delta
    sensory fi bers
    B. Ischemic pain is produced by overstimulating somatic
    touch receptors
    C. Ischemic pain is transmitted to the brain through the
    neospinothalamic tract
    D. Ischemic pain receptors quickly adapt to a painful
    stimulus
    E. Ischemic pain sensory fi bers terminate within the substantia
    gelatinosa of the spinal cord
A
  1. Answer: E
    Explanation:
    (Guyton, pp 552-555.) Activating nociceptors on the free
    nerve endings of C fi bers produces ischemic pain. The C
    fi bers synapse on interneurons located within the
    substantia gelatinosa (laminas II and Ill)of the dorsal horn
    of the spinal cord.The pathway conveying ischemic pain
    to the brain is called the paleospinothalamic system. In
    contrast, well-localized pain sensations are carried within
    the neospinothalamic tract. Ischemic pain does not adapt to prolonged stimulation. Pain is produced by specifi c
    nociceptors and not by intense stimulation of other
    mechanical, thermal, or chemical receptors.
124
Q
  1. The following statement is false regarding the NMDA
    receptor:
    A. Dorsal horn NMDA receptors are not functional unless
    there has been a large scale release of glutamate from
    primary afferent terminals.
    B. In the dormant state NMDA receptor channels are
    blocked by a Mg++ plug.
    C. Once opened, the most important ion passing through
    the NMDA receptor channel is Na+.
    D. Ketamine causes a noncompetitive blockade of the ion
    channel in the NMDA receptor.
    E. Activation of NMDA receptors is an early step in the
    evolution of central hypersensitivity.
A
  1. Answer: C
    Explanation:
    Reference:
    Yaksh, Tony in Waldman, Interventional Pain
    Management, Second Edition; Chapter 2, pp. 11-19.
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Spinal Mechanisms and their Modulation. pp. 87-90.
    Evidence suggests that prolonged afferent stimulation by
    nociceptive afferents triggers activation of NMDA (Nmethyl-
    D-aspartate)receptors which in turn activate WDR
    interneurons. The main neurotransmitter used by
    nociceptive afferents synapsing within the dorsal horn is
    glutamate, a versatile molecule that can bind to several
    different classes of receptors. Those most involved in the
    sensation of acute pain, AMPA (alpha-amino-3-hydroxy-
    5-methyl-isoxazole-4-propionic-acid) receptors, are
    always exposed on afferent nerve terminals. When AMPA
    receptors are bound by glutamate, they open allowing Na+
    ions to enter the cell. In contrast, receptors most involved
    in the sensation of chronic pain, NMDA receptors, are not
    functional unless there has been a persistent or large-scale
    release of glutamate. Repeated activation of AMPA
    receptors dislodges magnesium ions that act like stoppers
    in transmembrane sodium and calcium channels of the
    NMDA receptor complex. The conformational change in
    the neuronal membrane opens the.NMDA receptor
    channel to Ca++ ions which fl ow into the cell that makes
    these receptors susceptible to stimulation is the fi rst step in
    central hypersensitization (Figure 3) and may mark the
    transition from acute to chronic pain.
    The complex structure of the NMDA receptor makes it
    susceptible to antagonism through a number of different
    mechanisms. Ketamine and dextromethorphan create a
    noncompetitive blockade of the ion channel within the
    receptor complex.
    Source: Schultz D, Board Review 2004
125
Q
  1. During a voluntary movement, the Golgi tendon organ
    provides the central nervous system with information
    about
    A. The length of the muscle being moved
    B. The velocity of the movement
    C. The blood fl ow to the muscle being moved
    D. The tension developed by the muscle being moved
    E. The change in joint angle produced by the movement
A
  1. Answer: D
    Explanation:
    (Berne, 3/e, pp 118-121.) The Golgi tendon organ (GTO)
    is located in the tendon of skeletal muscles and therefore is
    in series with the muscle. Each time the muscle contracts,
    the tension developed by the muscle causes the GTO to be
    stretched. The Ib afferent fi bers, which innervate the GTO,
    fi re in proportion to the amount of GTO stretch, and
    therefore their fi ring rate provides the CNS with
    information about the amount of tension developed by
    the muscle. The muscle length and speed of shortening are
    sent to the CNS by Ia afferents that innervate the intrafusal
    fi bers within muscle spindles.
126
Q
331. The treatment of choice of rapid cycling bipolar disorder is
A. Carbamazepine
B. Lithium
C. Clonazepam
D. Haloperidol
E. Valproic acid
A
  1. Answer: E
    Explanation:
    Valproate can also be useful in the treatment of AIDSrelated
    mania. Valproic acid was approved by the FDA for
    the treatment of acute mania. A therapeutic blood-level window of 45 to 125 mug/mL has been demonstrated to
    correlate with antimanic response. Valproate might have
    better effi cacy than lithium in the treatment of mixed
    manic states, rapid cycling mania or other complex,
    comorbid forms of bipolar disorder, and could synergize
    with lithium to prevent relapses.
    Source: Laxmaiah Manchikanti, MD
127
Q
  1. The true statements about the cerebrospinal fl uid (CSF) are
    A. It is absorbed by the choroid plexus
    B. Its absorption is independent of CSF pressure
    C. It circulates in the epidural space
    D. It has a lower glucose concentration than plasma
    E. It has a higher protein concentration than plasma
A
  1. Answer: D
    Explanation:
    (Guyton, pp 711-714.)
    A. Cerebrospinal fl uid (CSF), which is in osmotic
    equilibrium with the extracellular fl uid of the b spinal
    cord, is formed primarily in the choroid plexus by an
    active process.
    B.It circulates through the subarachnoid space between
    mater and pia mater and is absorbed into the circulation
    by the arachnoid villi.
    C. The epidural space, which lies outside the dura mater,
    may be used clinically for injection of anesthetics and
    steroids.
    D. CSF protein and glucose concentrations are much
    lower than those of plasma. Changes in those
    concentrations in the CSF are helpful in detecting
    pathologic processes, such as tumor or infection, in which
    the blood-brain barrier is disrupted.
    E. CSF protein and glucose concentrations are much lower
    than those of plasma. Changes in those concentrations in
    the CSF are helpful in detecting pathologic processes, such
    as tumor or infection, in which the blood-brain barrier is
    disrupted
128
Q
  1. The activities placing the greatest load on the L3 disc
    include:
    A. Extension of 20°
    B. Lifting 20 kg, back straight, knees bent
    C. Lifting 20 kg, back bent, knees straight
    D. Bending forward 20°
    E. Bending sideways
A
333. Answer: C
Explanation:
The loads on a L3 disc in a 70-kg person are as follows:
supine 30 kg;
standing 70 kg;
upright sitting without support 100 kg;
walking 85 kg;
bending sideways 95 kg;
jumping 110 kg;
bending forward 20° 120 kg;
lifting 20 kg with back straight and knees bent 210 kg;
lifting 20 kg with back bent and knees straight 340 kg
Source: Bonica
129
Q
  1. Special receptors in the walls of the aortic arch and
    carotid arteries convey information concerning mean
    arterial blood pressure to refl ex pathways in the CNS. The
    afferent limb of this pathway is carried by
    A. CN V
    B. CN VII
    C. CN IX
    D. CN X
    E. CN XI
A
  1. Answer: C
    Explanation:
    (Waxman, 24/e, p 256.)Information from baroreceptors in
    the vascular wall passes via cardiac depressor nerves to
    the glossopharyngeal nerve (CN IX). The cell bodies of
    these neurons are located in the petrosal ganglion, and
    their central processes terminate on second-order
    interneurons in the nucleus of the solitary tract. These interneurons project to preganglionic parasympathetic
    cardioinhibitory neurons in the nucleus ambiguus, which
    reach ganglia on the surface of the heart via CN X (vagus
    nerve) and branches of the cardiac plexus. CN V
    (trigeminal) carries general somatic afferents from the
    face and innervates muscles involved in mastication. CN
    VII (facial) innervates the muscles of facial expression. CN
    XI primarily innervates the trapezius and
    sternocleidomastoid muscles.
    Source: Klein RM and McKenzie JC 2002.
130
Q
335. A 20-year-old male with herpes simplex of the lips is
treated with famciclovir. What is the mechanism of
action of famciclovir?
A. Cross-linking of DNA
B. Strand breakage of DNA
C. Inhibition of viral DNA synthesis
D. Inhibition of viral kinase
E. Activiation of viral DNA synthesis
A
  1. Answer: C
    Explanation:
    Reference: Katzung, pp 827-828.
    Famciclovir is active against herpes simplex and varicella
    zoster viruses. It is activated by a viral kinase to a
    triphosphate. The triphosphate is a competitive substrate
    for DNA polymerase.The incorporation of the famciclovir
    triphosphate into viral DNA results in chain termination.
    Source: Stern-2004
131
Q
  1. A patient presents with an acute onset of medial forearm pain. On physical exam he demonstrates a positive
    Froment’s sign and loss of sensation in little fi nger. Neck
    rotation and lateral fl exion worsens the arms pain. An
    MRI of the neck confi rms the presence of a paracentral
    disc protrusion at which level?
    A. C4-5
    B. C5-6
    C. C6-7
    D. C7-T1
    E. C3-4
A
  1. Answer: E
    Source: (Raj, Pain Review, 2nd Ed. Page 62; Bonica, 3rd
    Ed., page 1089)
132
Q
  1. Allodynia is defined as:
    A. Spontaneous pain in an area or a region that is anesthetic
    B. Hypersensitivity to a painful stimulus
    C. Pain initiated or caused by a primary lesion or dysfunction in the nervous system
    D. An unpleasant abnormal sensation, whether spontaneous or evoked.
    E. Pain caused by a stimulus that does not normally provoke pain.
A
  1. Answer: E
    Explanation:
    The International Association for the Study of Pain has
    defi ned several pain terms.
    A. Spontaneous pain is an area or region that is anesthetic
    is called anesthesia dolorosa
    B. Hypersensitivity to a painful stimulus is called
    hyperalgesia
    C. Pain initiated or caused by a primary lesion or
    dysfunction in the nervous system is called neuropathic
    pain
    D. An unpleasant abnormal sensation, whether
    spontaneous or evoked is called dysesthesia
    E. The perception of pain produced by stimuli that are
    usually non-painful is called allodynia
133
Q
338. Cholinergic receptors are divided into the following two categories
A. Nicotinic and adrenergic
B. Adrenergic and muscarinic
C. Cholinergic and adrenergic
D. Nicotinic and muscarinic
E. None of the above
A
  1. Answer: D
    Source: Raj P, Pain medicine - A comprehensive Review -
    Second Edition
134
Q
  1. Repetitive stimulation of a skeletal muscle fi ber will cause an increase in contractile strength because repetitive
    stimulation causes an increase in
    A. The duration of cross-bridge cycling
    B. The concentration of calcium in the myoplasm
    C. The magnitude of the end-plate potential
    D. The number of muscle myofi brils generating tension
    E. The velocity of muscle contraction
A
  1. Answer: A
    Explanation:
    (Berne, 3/e, pp 155-158.) Each time a skeletal muscle fi ber
    is stimulated by an alpha motoneuron, enough Ca2+ is
    released from its sarcoplasmic reticulum (SR) to fully
    activate all the troponin within the muscle. Therefore,
    every cross bridge can contribute to the generation of
    tension. However, the transmission of force from the cross
    bridges to the tendon (or bone or measuring device) does
    not occur until the series elastic component (SEC) of the
    muscle is stretched. Repetitive fi ring increases the amount
    of SEC stretch by maintaining cross-bridge cycling for a
    longer period of time. This occurs because each time the
    muscle is activated, the Ca2+ released from the SR
    replaces the Ca2+ that has been resequestered since the last
    stimulus. Repetitive fi ring increases neither the
    concentration of Ca2+ within the myoplasm, the number
    of myofi brils that are activated, nor the magnitude of the
    end-plate potential. Because all of the cross bridges are
    activated each time a skeletal muscle fi ber is activated, an
    increase in Ca2+ concentration would have no effect on
    muscle strength.
135
Q
  1. A 29-year-old female has a 10-year history of migraine
    headaches. She can usually sense onset. Which of the
    following agents is the drug of choice for countering
    acute onset of her headaches?
    A. Ergotamine
    B. Propranolol
    C. Methysergide
    D. Pseudoephedrine
    E. Aspirin
A
  1. Answer: A
    Explanation:
    Reference: Hardman, p 495.
    Explanation: Ergotamine has several pharmacologic
    properties, including the blockade of a-adrenergic
    receptors; however, its mechanism of action in treating
    migraine headaches is primarily related to its agonistic
    interaction with serotonin receptors (5-HT1D), resulting
    in vasoconstriction. Although chronic treatment with this
    nonsedative, nonanalgesic drug does not decrease the
    frequency of or prevent migraine attacks, an oral dose of
    ergotamine is the drug of choice for combating an
    incipient attack of migraine headache, especially during
    the prodromal stage.
    Source: Stern - 2004
136
Q
341. The cell body of the neospinothalamic tract is located in which lamina?
A. II
B. III
C. IV
D. V
E. VII
A
  1. Answer: D
    Source: Raj P, Pain medicine - A comprehensive Review -
    Second Edition
137
Q
  1. The efferent limb of the cremaster refl ex is provided by the
    A. Femoral branch of the genitofemoral nerve
    B. Genital branch of the genitofemoral nerve
    C. Ilioinguinal nerve
    D. Pudendal nerve
    E. Temperature differential between core body temperature
    and scrotal temperature
    Directions: Each question below contains four suggested
    responses of which one or more is correct. Select
    A if 1, 2 and 3 are correct
    B if 1 and 3 are correct
    C if 2 and 4 are correct
    D if 4 is correct
    E if All (1, 2, 3 and 4) are correct
A
  1. Answer: B
    Explanation:
    (April, 3/e, p 429.) The cremaster refl ex is mediated by the
    genitofemoral nerve. The femoral branch supplies the
    afferent limb, and the genital branch supplies the efferent
    limb. The ilioinguinal nerve provides sensory innervation
    to the medial aspects of the thigh and the anterior aspects
    of the mons or the base of the penis. The pudendal nerve
    provides sensation to most of the skin of the perineum as
    well as the motor supply to the perineal muscles. The
    involuntary scrotal refl ex is based on temperature: warmth
    causes relaxation of the dartos muscle, whereas cold
    causes contraction.
    Source: Klein RM and McKenzie JC 2002.
138
Q
  1. What is the underlying focus in the clinical assessment
    of pain?
  2. Objectify a subjective variable
  3. Recognize and quantify qualitative phenomena
  4. Correlation of medical fi ndings (eg.- clinical tests) with
    patient history and complaint(s)
  5. Filter and reduce patient reports in favor of objective
    tests
A
  1. Answer: A (1, 2 & 3)
    Explanation:
    Pain assessment focuses upon quantifying primarily
    qualitative variables that have unique subjective
    experience for each patient. Attribution of such fi ndings to
    particular pathologies is accomplished by relating clinical
    fi ndings with patients’ subjective reports of the nature,
    extent, and characteristics of their pain.
    Source: Giordano J, Board Review 2005
139
Q
  1. Based upon a mechanistic knowledge of pain transmission
    and conduction, why would the clinician expect a
    diabetic patient to have heightened sensations of durable
    neuropathic pain?
  2. Polyol sugar- induced disruption of Na-K ATPase function
  3. Increase in A-beta fi ber function
  4. Hyper sensitization of C-fi bers caused by enhanced
    sodium fl ux and membrane conductance
  5. Loss of C-fi ber conductivity
A
  1. Answer: B (1 & 3)
    Explanation:
    Disruption of glucose metabolism yields increased polyol
    end products that are incorporated into neural
    membranes and disrupt ionic gradients by interfering
    with the Na-K ATPase function. This can lead to enhanced sodium fl ux
    and membrane conductance, primarily in unmyelinated
    nociceptive afferents (C-fi bers).
    Source: Giordano J, Board Review 2005
140
Q
  1. A patient is taking part in a sleep study. When the patient begins to dream, the following physiologic change would be expected:
  2. Increase in sternocleidomastoid tonus
  3. More visual imagery during non-REM (NREM) sleep
  4. Delta waves on electroencephalogram
  5. Electroencephalographic desynchrony
A
  1. Answer: D (4 Only)
    Explanation:
    (Kandel, pp 945-946.)
    The physiologic responses to dreaming listed in the
    question can easily be recorded in most people several
    times each night. If awakened at such times, people usually
    confi rm that they were dreaming.
    A. The complex of physiologic signs (e.g.,
    electroencephalographic desynchrony, rapid eye
    movements, loss of muscle tonus, and cardiorespiratory
    irregularities) is commonly referred to as REM sleep or
    paradoxical sleep.
    The term paradoxical sleep was applied originally
    because the associated electroencephalographic pattern is
    characteristic of the alert waking state even though the
    dreaming person is, in fact, sound asleep.
    Dreams occurring during NREM sleep are less easily
    recalled, less vivid, less visual, less emotional, and more
    pleasant.
    Source: Ebert 2004
141
Q
  1. Prolonged activation of the NK-1 receptor by Substance- P has been shown to:
  2. Sensitize post-synaptic NMDA receptors to mediate
    summatory responses
  3. Possibly activate proto-oncogenes responsible for synaptic
    facilitation.
  4. Result or most likely occur in type III pain
  5. Up-regulate dynorphin receptors on spinal interneurons
A
  1. Answer: D (4 Only)

Source: Giordano J, Board Review 2003

142
Q
  1. Both cerebral hemispheres are destroyed, but the brain stem is relatively intact. Many of these patients are
    unresponsive for the first few weeks, and then stabilize
    into an “eyes-open unconsciousness”, with complete
    lack of cognition. They do have wake-sleep cycles,
    eye movements, intact reflexes, pupillary responses
    and spontaneous respirations. Choose the correct
    statements.
  2. Coma
  3. Semi-coma
  4. Brain Death
  5. Permanent Vegetative State (PVS)
A
  1. Answer: D (4 Only)
143
Q
  1. The patellar jerk or knee refl ex is innervated by:
  2. L2
  3. L5
  4. L3
  5. L4
A
  1. Answer: D (4 Only)
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT
    p.256.
144
Q
  1. Saltatory conduction is correctly described by the
    following.
  2. It occurs in myelinated nerves
  3. It occurs in unmyelinated nerves
  4. It greatly increases the velocity of nerve conduction
  5. It expends more energy
A
  1. Answer: B (1 & 3)
    Explanation:
    The successive excitation of nodes of Ranvier by an
    impulse that jumps between successive nodes is termed
    saltatory conduction.
    1, 2. Action potentials are conducted from node to node by
    myelinated nerves rather than continuously along the
    entire fi ber as occurs in the unmyelinated nerve.
  2. Saltatory conduction greatly increases the velocity of
    nerve transmission in myelinated fi bers.
  3. Saltatory conduction conserves energy because only the
    nodes of Ranvier depolarize, resulting in lower loss of ions
    than would otherwise occur.
    Source: Kahn and Desio
145
Q
  1. What are the main types of cervical spine pathology
    found in rheumatoid arthritis?
  2. atlanto-axial subluxation
  3. cranial settling
  4. subaxial subluxation
  5. posterior longitudinal ligament thickening and hypertrophy
A
  1. Answer: A (1, 2, & 3)

Source: (Bonica, 3rd Ed., page 1010)

146
Q
  1. All the following are true regarding visceral pain.
  2. Traction and distention usually produce pain
  3. Pain can commonly be referred
  4. Pain is diffuse and poorly localized
  5. Viscera have fewer nociceptors than somatic structures
A
  1. Answer: E (All)
    Explanation:
    There are signifi cant clinical differences between visceral
    and cutaneous nociception.
  2. Cutting and burning of mesentery, the uterine cervix, or
    other visceral organs do not necessarily produce clinical
    pain. However, traction, distention, or ischemia will
    produce this type of pain.
  3. The visceral nociceptors have wide receptive fi elds that
    prevent accurate localization of visceral sensation, which
    may explain the phenomenon of referred pain.
  4. This pain is often diffuse and poorly localized and often
    has a signifi cant autonomic component.
  5. There are fewer nociceptors in the viscera than in the
    skin, and these receptors may have a different activation
    profi le.
147
Q
  1. The complex nociceptive system is balanced by an
    equally complex anti-nociceptive system which makes
    up the internal pain control apparatus. The following
    statements are true regarding modulation of nociceptive
    transmission:
  2. Pain signals arriving from peripheral tissues stimulate
    the release of endorphins in the periaqueductal gray
    matter of the brain and enkephalins in the nucleus
    raphe magnus of the brainstem.
  3. Endorphins inhibit propagation of nociception by binding
    to presynaptic mu-receptors on primary afferent
    terminals and post-synaptic receptors on dorsal horn
    interneurons.
  4. Enkephalins bind to delta receptors on inhibitory interneurons
    in the substantia gelatinosa causing release of
    GABA and other chemicals that inhibit neurotransmitter
    release.
  5. Enkephalin initiates the release of dynorphin which
    activates kappa opioid receptors on inhibitory interneurons.
A
  1. Answer: E (All)
    Explanation:
    Reference:
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Spinal Mechanisms and their Modulation.
    Anti-nociceptive pathways are activated when pain signals
    ascending in the ventrolateral tracts reach the brain stem
    and thalamus. Stimulation of the periventricular gray area
    in the thalamus and the nucleus raphe magnus in the
    brain stem stimulates release of endorphins and
    enkephalins respectively. These ligands bind to their
    respective receptors and initiate a series of physiochemical
    changes that inhibit pain transmission in the spinal cord as
    outlined in answers 1-4 above.
    Since 70% of the endorphin and enkephalin receptors are
    located in the presynaptic membranes of nociceptive
    afferent terminals, most of the pain transmission is
    stopped before it reaches the dorsal horn. The pain signals
    that get through are further weakened by enkephalininduced
    dynorphin activity in the spinal cord. Dynorphin
    activation of kappa receptors on inhibitory interneurons
    causes release of GABA which hyperpolarizes dorsal horn
    cells and further inhibits pain transmission.
    Source: Schultz D, Board Review 2004
148
Q
  1. Nerve fi bers primarily responsible for the transmission of pain impulses include
  2. A-beta fi bers
  3. A-delta fi bers
  4. B fi bers
  5. C fi bers
A
  1. Answer: C (2 & 4)
149
Q
  1. Repetitive local stimulation and/or injury of peripheral
    tissues can cause the “triple response” characterized by:
    · A red fl ush (fl are) around the site of the stimulus·
    Local edema (wheal)· Local hyperalgesiaThe following
    statements are true regarding this phenomenon:
  2. Tissue damage causes increased capillary permeability
    with extravasation of histamine, bradykinin and lipidic
    acids.
  3. C-fi ber afferents in the region become sensitized and
    can be activated by relatively mild stimuli
  4. Substance P and calcitonin G-related peptide (CGRP)
    are infl ammatory agents contained within and released
    from C fi ber terminals
  5. C-polymodal nociceptors adapt to continuous repetitive
    stimulation and become less responsive to further
    stimuli.
A
  1. Answer: A ( 1, 2, & 3)
    Explanation:
    Reference:
    Yaksh, Tony in Waldman, Interventional Pain
    Management, Second Edition; Chapter 2, pp. 11-19.
  2. Changes occur in peripheral tissue with injury and/or
    with repetitive stimulation of C-fi bers. Tissue damage
    causes increased capillary permeability with extravasation
    of histamine, kinins, lipidic acids cytokines and a host of
    inflammatory peptides.
  3. Stimulation of C-fi bers results in release of these injury
    products into tissues.
    - The release of infl ammatory mediators into tissues
    results in an infl ammatory milieu with the following
    effects:
  4. Local edema
  5. Local erythema
  6. Hyperalgesia
    - This reaction is called “the triple response of Lewis.
    It can be triggered by local axon refl exes from activation
    of C-fi bers or from tissue injury.
    The majority of C-fi bers, called “silent nociceptors”,
    have little or no spontaneous activity and are activated
    only by extremely intense physical stimuli.
    - In the presence of infl ammation C-fi ber terminals
    become sensitized and are activated by mild stimuli.
    This creates a state referred to as hyperalgesia.
  7. Infl ammatory mediators including substance P,
    glutamate, VIP, somatostatin, CGRP and bombesin are
    contained within the terminals of C-fi bers.
  8. C-fi bers do not adapt to repetitive stimuli but instead
    remain sensitized as long as the infl ammatory
    environment is present.
    Source: Schultz D, Board Review 2004
150
Q
  1. The following statements are true regarding C-polymodal
    nociceptors:
  2. They are called polymodal because they respond to a
    variety of innocuous low threshold as well as noxious
    high threshold stimuli.
  3. The distal axons arborize into unspecialized free nerve
    endings in peripheral tissue.
  4. The central axons connect to interneurons primarily in
    Rexed’s lamina III and VI in the dorsal horn.
  5. They are unipolar neurons with cell bodies that reside in
    the dorsal root ganglion.
A
  1. Answer: C (2 & 4)
    Explanation:
    Reference:
    Yaksh, Tony in Waldman, Interventional Pain
    Management, Second Edition; Chapter 2, pp. 11-19.
  2. C-polymodal nociceptors are slow-conducting,
    unmyelinated fi bers that are activated only by high
    threshold stimulation.
    - They are not activated by low threshold stimuli.
    -They are called polymodal because they are activated by
    a variety of noxious, nociceptive chemical, mechanical and
    thermal stimuli.
    * These neurons are pseudounipolar with cell bodies
    residing in the dorsal root ganglion.
  3. A short stem connects the cell body to the peripheral
    axon which travels out to the peripheral tissues where it
    arborizes into unspecialized free nerve endings.
  4. Central axons synapse with dorsal horn neurons
    primarily in Rexed’s lamina I (called the marginal zone), II
    (called the substantia gelatinosa) and V (which along with
    lamina III and IV, make up the nucleus proprius).
  5. They are unipolar neurons with cell bodies that reside in
    the dorsal root ganglion.
    Source: Schultz D, Board Review 2004
151
Q
  1. Enkephalins are found in the
  2. Lungs
  3. CNS
  4. Bladder
  5. adrenal medulla
A
  1. Answer: C (2 & 4)
    Explanation:
    Endogenous opiods modulate nociception.All endogenous
    opioids contain the amino acid sequence tyrosine-glycinephenylanine.
    They are cleaved from three precursor
    molecules: proenkephalin A, proopiomelanocortin, and
    prodynorphin (proenkephalin B).
    Proenkephalin A is cleaved to form met- and leuenkephalins.
    Prodynorphin is cleaved to form dynorphin and alphaneoendorphin,
    which are not potent analgesics. They are
    found in the same distribution as the enkephalins. Their
    function has not been fully determined.
  2. Enkephalins are found in highest concentration in the
    GI tract, sympathetic nervous system, adrenal medulla,
    periaqueductal gray, the rostroventral medulla, and
    Rexed’s laminae I, II, V, and X.
  3. Beta-endorphin, which is derived from
    proopiomelanocortin, is released from the pituitary gland
    along with ACTH. It is the most potent opiod and is found
    in high concentrations in the hypothalamus,
    periaqueductal gray, and locus ceruleus.
152
Q
  1. True statement(s) concerning peripheral nerve structure
    and function include of the following:
  2. Both nonmyelinated and myelinated nerves are surrounded
    by Schwann cells
  3. The speed of propagation of an action potential along a
    nerve axon is greatly enhanced by myelin
  4. Generation of an action potential is an “all-or-nothing”
    phenomenon
  5. Propagation of an action potential along myelinated
    nerve axons occurs by saltatory conduction via the
    nodes of Ranvier
A
  1. Answer: E (All)
    Explanation:
  2. Peripheral nerve axons are always enveloped by a
    Schwann cell.
    - The myelinated nerves may be enveloped many times by
    the same Schwann cell.
  3. Transmission of nerve impulses (i.e., action potentials)
    along nonmyelinated nerves occurs in a continuous
    fashion, whereas transmission along myelinated nerves
    occurs by saltatory conduction from one node of Ranvier
    to the next.
    - Myelination speeds transmission of neurological
    impulses; it also renders nerves more susceptible to local
    anesthetic blockade.
  4. An action potential is associated with an inward fl ux of
    sodium that occurs after a certain membrane threshold
    has been exceeded.
  5. Propagation of an action potential along myelinated
    nerve axons occurs by saltatory conduction via the nodes
    of Ranvier.
    Ref.: Hall and Chantigan.
153
Q
  1. The parasympathetic nervous system includes
  2. axons that travel with the accessory nerve
  3. cell bodies of preganglionic fi bers in cranial nerve nuclei
  4. short preganglionic fi bers
  5. cell bodies in the intermediolateral gray area of the
    sacral spinal cord
A
  1. Answer: C (2 & 4)
    Explanation:
    The parasympathetic nervous system consists of cranial
    and sacral portions.
    The cell bodies of preganglionic parasympathetic fi bers are
    located in cranial nerve nuclei of the brainstem. The long
    preganglionic fi bers of the oculomotor, facial, and
    glossopharyngeal nerves synapse with short postganglionic fi bers of the ciliary, sphenopalatine, and
    otic ganglia. The very long preganglionic fi bers of the
    vagus synapse in intramural ganglia of the heart, lungs,
    and gastrointestinal tract.
    Preganglionic neurons of the sacral portion of the
    parasympathetic nervous system have cell bodies located
    inthe intermediolateral gray of the second, third, and
    fourth sacral cord segments.
    Source: Kahn and Desio
154
Q
359. The major anatomic areas of the CNS involved in opioidmediated
analgesia include the
1. periventricular region
2. rostroventral medulla
3. periaqueductal gray matter
4. thalamus
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    - Extrogenously administered opioids exert their
    analgesic effects by acting directly on the CNS.
    - The major anatomic areas involved in opioid-mediated
    analgesia include the periventricular and periaqueductal
    gray matter and the rostroventral medulla.
155
Q
  1. True statements regarding serotonin include
  2. it is found in the rostroventral medulla
  3. it inhibits nociceptive neurons in laminae V and X
  4. it is involved in descending antinociceptive pathways
  5. its direct application to the spinal cord has no effect on
    pain
A
  1. Answer: B (1 & 3)
    Explanation:
  2. The rostroventral medulla is rich in serotonergic
    neurons that project to the spinal cord.
  3. Stimulation of neurons in the rostroventral medulla
    with serotonergic terminals in the dorsal horn inhibits
    nociceptive neurons in laminae I and II.
  4. Serotonin is a neurotransmitter in descending
    antinociceptive pathways.
  5. Application of serotonin to the spinal cord inhibits
    discharge of spinothalamic tract neurons and relieves pain.
156
Q
  1. The true statements about the reticular formation are:
  2. It regulates motor, sensory, and autonomic functions
  3. It consists of nuclei located in the brainstem
  4. It responds to noxious stimulation
  5. It is involved with the affective component of pain
A
  1. Answer: E (All)
    Explanation:
  2. The reticular formation participates in the regulation of
    motor, sensory, and autonomic functions.
  3. The reticular formation consists of a number of vaguely
    defi ned nuclei situated in the core of the brainstem and
    extending throughout its rostrocaudal aspect.
  4. Many reticular neurons respond to noxious stimulation,
    and many respond exclusively to specifi c noxious
    modalities.
  5. The reticular formation is thought to participate in the
    affective/motivational component of pain and in the
    integration of pain with autonomic and motor behavior.
157
Q
  1. Ascending nociceptive pathways in the anterolateral
    quadrant (ALQ) of the spinal cord include the
  2. spinothalamic tract
  3. spinomesencephalic tract
  4. spinoreticular tract
  5. spinomedullary system
A
  1. Answer: E (All)
    Explanation:
    The major ascending nociceptive tract in the anterolateral
    quadrant (ALQ) is the spinothalamic tract (STT). Other
    tracts of the ALQ that are thought to be involved in pain
    perception are:
    - the spinoreticular tract (SRT),
    the spinomesencephalic tract (SMT),
    - the dorsal column postsynaptic spinomedullary system,
    and
    - the propriospinal multisynaptic ascending system.
    Source: Kahn and Desio
158
Q
  1. Laminae I, II, and V in the dorsal horn
  2. project to the brainstem
  3. abolish cutaneous pain when cut
  4. produce analgesia when stimulated
  5. are major areas for convergence of nociceptive transmission
A
  1. Answer: C (2 & 4)
    Explanation:
  2. Laminae I, II, and V are the major areas for convergence
    of nociceptive transmission at the spinal cord.
  3. Cells from these areas project to the thalamus, and
    cutting this projection abolishes cutaneous pain.
  4. Stimulating the projections of laminae I and II produces
    pain.
  5. Discharge of these cells increases with increasing
    noxious stimulation.
    - In response to a brief noxious stimulus, laminae I and V
    neurons have early and late discharges, analogous to fi rst
    and second pain.
159
Q
  1. Cells found in the dorsal horn include
  2. excitatory interneurons
  3. inhibitory interneurons
  4. projection cells
  5. wide dynamic range (WDR) neurons
A
  1. Answer: E (All)
    Explanation:
    Three classes of cells are found in the dorsal horn:
  2. Excitatory interneurons relay nociceptive transmission
    to projection cells, to other interneurons, or to motor cells
    concerned with refl exes
  3. Inhibitory interneurons modulate nociceptive
    tranmission.
  4. Projection cells relay information to rostral center
  5. Other cells in the dorsal horn receive additional input
    from nonnociceptive afferents. These cells are called wide
    dynamic range (WDR) neurons and respond to a wide
    range of stimuli from low to high intensity.
160
Q
  1. Bradykinin, a peptide produced by activation of the kinin system,
  2. decreases vascular permeability
  3. has binding sites in the dorsal horn
  4. inhibits leukocyte chemotaxis
  5. is produced as sites of tissue injury
A
  1. Answer: C (2 & 4)
    Explanation:
    -Bradykinin is a 9-amino acid peptide produced at sites of
    tissue injury by enzymatic action.
    - Bradykinin produces pain in humans at concentrations
    equivalent to those found in injured tissue.
    - Binding sites for bradykinin are found on sensory fi bers
    and in the dorsal horn.
  2. Bradykinin increases vascular permeability.
  3. Bradykinin has binding sites in the dorsal horn.
  4. Bradykinin enhances leukocyte chemotaxis, and
    sensitizes nociceptors.
  5. Bradykinin is produced as sites of tissue injury.
    Source: Kahn and Desio
161
Q
  1. Cranial nerves involved in the corneal refl ex include
  2. 7th cranial nerve
  3. 3rd cranial nerve
  4. 5th cranial nerve
  5. 6th cranial nerve
A
  1. Answer: B (1 & 3)
    Explanation:
  2. The efferent limb is mediated by the facial nerve (7th
    cranial), which conveys the impulse to the orbicularis
    oculi.
  3. The afferent limb of the refl ex is the ophthalmic
    division of the trigeminal nerve (5th cranial).
162
Q
  1. All of the following are true regarding the intervertebral discs
  2. They have multiple innervations
  3. Intradiscal pressure raises over night
  4. Intradiscal pressure decreases with standing in fl exion
  5. Intradiscal pressure raises with valsalva
A
  1. Answer: A (1, 2, & 3)

Source: Rozen. Pain Practice: SEP 2001

163
Q
  1. A patient has atypical facial pain of fi ve years duration.
    She experiences continuous burning pain in the right
    mid face and right forehead. When pain is severe, she also
    feels pain in the right occiput. The following statements
    are more than likely true:
  2. The central processes of the involved pain fi bers synapse
    in the subnucleus caudalis portion of the cervicotrigeminal
    nucleus
  3. The cell bodies of the nociceptive afferent fi bers transmitting her pain reside in the trigeminal ganglion.
  4. V2 is most likely involved in pain transmission.
  5. The occipital pain can be explained by convergence of
    trigeminal fi bers and C2 nerve root fi bers onto interneurons in the pons.
A
  1. Answer: A ( 1, 2, & 3)
    Explanation:
    Reference:
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Peripheral Pain Mechanisms and Nociceptor Plasticity. pp.
    37-38
    In many respects, the anatomy, physiology and
    biochemistry of cranial nociception is homologous to pain
    pathways in the rest of the body. Transmission of pain in
    the anterior two thirds of the head occurs primarily
    through the trigeminal system. The trigeminal ganglion
    houses the cell bodies of pseudounipolar A-delta and Cfi
    ber axons which exit the ganglion and innervate the
    anterior head, traveling outward within the three divisions
    of the trigeminal system: the ophthalmic (V1), maxillary
    (V2) and mandibular (V3) nerves.
  2. The central processes of these axons exit the ganglion
    and travel into the subnucleus caudalis portion of the
    trigeminocervical nucleus (spinal nucleus V) where they
    synapse with interneurons.
  3. The cell bodies of the nociceptive afferent fi bers
    transmitting her pain reside in the trigeminal ganglion.
  4. V2 is most likely involved in pain transmission.
  5. Pain sensation in the posterior upper neck and occipital
    region is transmitted by the upper cervical nerve roots
    especially C2.
    - The C2 dorsal root ganglion contains the cell bodies of
    nociceptive afferents, the central processes of which
    synapse in the subnucleus caudalis on the same
    interneuron pool as the trigeminal nociceptive fi bers.
    - This explains why anterior face pain transmitted via the
    trigeminal system can cause occipital referred pain and
    also why posterior neck pain can sometimes be referred to
    the face.
    Source: Schultz D, Board Review 2004
164
Q
  1. Acetylcholine is released at
  2. preganglionic parasympathetic nerve endings
  3. preganglionic sympathetic nerve endings
  4. postganglionic parasympathetic nerve endings
  5. postganglionic sympathetic nerve endings
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
  2. Acetylcholine is released at all preganglionic nerve
    endings (both sympathetic and parasympathetic)
  3. Acetylcholine is released at preganglionic sympathetic nerve endings.
  4. Acetylcholine is released at postganglionic
    parasympathetic nerve endings.
    - Sympathetic postganglionic innervation to sweat
    glands is also cholinergic.
  5. Norepinephrine is the neurotransmitter found in
    postganglionic sympathetic nerve endings.
165
Q
  1. A-delta fi bers subtend:
  2. High threshold mechanical input
  3. Lo-medium threshold mechanical input
  4. High threshold thermal input
  5. Polymodal and chemical high threshold input
A
  1. Answer: B (1 & 3)
    Explanation:
    There are two types of A-delta fi bers: Those that subtend
    high threshold tensile and/or compressive mechanical
    stimuli and those that transduce noxious cold (< 24o C
    and > 45o C). A third population the mixed
    mechanothermal nociceptor is capable of responding to
    both types of noxious input.
    Medium threshold mechanical input is subserved by Abeta
    fi bers.
    Polymodal/ chemical high threshold input is subserved by
    C-fi bers.
    Source: Giordano J, Board Review 2005
166
Q
  1. Stimulation of the following receptors serves as a negative feedback mechanism
  2. Beta-1
  3. Beta-2
  4. Alpha-1
  5. Alpha-2
A
  1. Answer: D (4 Only)
    Explanation:
    1, 2. Activation of beta receptors results in relaxation of
    bronchial muscles and increases in cardiac rate and force
    of contraction.
  2. Activation of alpha receptors results in increased
    peripheral vascular resistance, mydriasis, and contraction
    of pilomotor muscles.
  3. The alpha-2 receptors are found in both presynaptic and
    postsynaptic locations. Stimulation of presynaptic alpha-2
    receptors inhibits norepinephrine release, serving as a
    negative feedback mechanism.
167
Q
  1. Which factors contribute to the sensory experience(s) of Type-II pain?
  2. Polymodal nature of the primary afferents that subserve
    Type-II pain
  3. Multiplicity of synaptic contacts within different types
    of second order afferents within the dorsal horn
  4. The distinct nature of the receptive fi eld of the primary
    afferents involved
  5. The possibility of after-discharges and summation of
    primary and second-order afferents
A
  1. Answer: E (All)
    Explanation:
    Type-II pain is a multi-dimensional neural event that is
    reliant upon peripheral and central sensitizing effects and
    the summative physiologic characteristics of both primary
    afferent and second-order neurons.
    Source: Giordano J, Board Review 2005
168
Q
  1. Neuronal excitability is enhanced by:
  2. Alkalosis
  3. inhaled anesthetics
  4. Hyperventilation
  5. hypoxemia
A
  1. Answer: B (1 & 3)
    Explanation:
    Neurons are highly responsive to changes in the pH of the
    surrounding interstitial fl uids.
  2. Alkalosis enhances neuronal excitability as does
    hyperventilation.
    Acidosis depresses neuron excitability.
  3. Inhaled anesthetics suppress neuronal excitability.
  4. Hyperventilation causes alkalosis and enhances
    neuronal excitability.
  5. Lack of oxygen can cause total inexcitability of neurons within 3 to 5 s.
169
Q
  1. Cranial tissues that are sensitive to pain include
  2. pia mater
  3. arteries of the dura mater
  4. brain parenchyma
  5. cranial sinuses and afferent veins
A
  1. Answer: C (2 & 4)
    Explanation:
    1, 3. Structures insensitive to pain include the intracranial
    structures of the parenchyma of the brain, ependyma,
    choroids plexus, pia mater, arachnoid membrane, and
    parts of the dura mater, as well as the extracranial
    skull (except for the periosteum, which is slightly painsensitive).
    2, 4. Pain-sensitive structures include such intracranial
    structures as the cranial sinuses and afferent veins, the
    arteries of the dura mater, the arteries of the base of the
    brain and their major branches, and parts of the dura
    mater in the vicinity of large vessels.
    Extracranial structures that are pain-sensitive include the
    skin, scalp, fascia, muscles, mucosa, arteries, and veins.
    - The trigeminal, facial, vagal, glossopharyngeal, and
    second and third cranial nerves are also sensitive.
    Source: Kahn and Desio
170
Q
  1. True statements about the changes that have been shown to take place after peripheral nerve injury include the following.
  2. The primary afferent nerve endings in the spinal cord
    sprout new connections within the dorsal horn
  3. Injured primary afferents may change neuropeptide
    production from substance P and calcitonin gene-related
    peptide (CGRP) to neuropeptide y, galanin, and
    vasoactive intestinal polypeptide (VIP)
  4. Upregulation of C-Fos in intrinsic spinal neurons occurs
  5. There is a large increase in the endogenous opioid
    dynorphin
A
  1. Answer: E (All)
    Explanation:
  2. All peripheral nerve injury appears to have a central
    effect. After peripheral nerve injury, the primary afferents
    arborize into new areas of the dorsal horn.
    2.In addition, they stop making substance P and CGRP
    and start making neuropeptide y, galanin, and VIP.
  3. There is upregulation of the early immediate gene CFos,
    which stimulates production of Fos protein.
  4. There is increased production of dynorphin by secondorder
    neurons.
    Source: Kahn CH, DeSio JM. PreTest Self Assessment and
    Review. Pain Management. New York, McGraw-Hill, Inc.,
    1996.
171
Q
  1. Correct statements regarding cell bodies include that
    those
  2. of somatic motor nerves lie in the anterior horn of the
    spinal cord
  3. of cranial nerves lie in the sensory neclei of the cranial
    nerve
  4. of somatic sensory nerves lie in the dorsal root ganglia
  5. of visceral sensory nerves lie in the autonomic nervous
    system
A
  1. Answer: B (1 & 3)
    Explanation:
    Cell bodies of somatic motor nerves lie in the anterior
    horn of the spinal cord or in motor nuclei of cranial
    nerves.
    Those of somatic sensory neurons reside in dorsal root
    ganglia, which are located in the intervertebral foramina.
    Sensory nerves subserving visceral sensation also have
    their cell bodies in dorsal root ganglia, through their
    axonal processes may travel with autonomic nerves to the
    periphery.
172
Q
  1. The following statements are true regarding WDR (wide
    dynamic range) neurons:
  2. They are dorsal horn interneurons that reside primarily
    in Rexed’s lamina V (the nucleus proprius).
  3. They are called convergence neurons and are thought to
    represent the neural basis for referred pain
  4. After receiving repetitive, low level stimulation from Cfi
    bers, they enter a state of continuous discharge called
    “wind up”.
  5. They are activated by low threshold, innocuous stimuli
    (light touch) as well as high threshold, nociceptive
    stimulation.
A
  1. Answer: E (All)
    Explanation:
    Reference:
    Bonica’s Management of Pain, Third Edition, Chapter 4, Spinal Mechanisms and their Modulation pp. 73-85
  2. Wide dynamic range (WDR) neurons are found mainly
    in dorsal horn lamina V (nucleus proprius).
  3. They are interneurons that have large cutaneuous as well
    as visceral receptive fi elds.
    - Single WDR neurons receive diverse input from various
    visceral and cutaneous tissues and are commonly called
    “convergence neurons”. They are thought to be responsible
    for the spinal component of referred pain.
  4. Low frequency, repetitive stimulation of C-fi bers
    produces a gradual increase in the frequency of WDR
    neuron activity until the neuron is in a state of virtually
    continuous discharge called “wind-up”.
  5. They are activated by innocuous as well as noxious
    stimuli. Light innocuous touch evokes activity that
    increases with the intensity of pressure or pinch into the
    noxious range.
    Source: Schultz D, Board Review 2004
173
Q
  1. True statements regarding serotonin include that it
  2. is an analgesic substance
  3. is released by platelets
  4. has no known antagonist
  5. has receptors located on peripheral nerves
A
  1. Answer: C (2 & 4)
    Explanation:
  2. Serotonin has been implicated as an algogenic
    substance.
  3. It is released by platelets in response to plateletactivating
    factor, a substance released by degranulating
    mast cells.
  4. Serotonin causes pain directly and by potentiation of
    the nociceptive effect of bradykinin.
  5. Serotonin receptors are found on peripheral nerves, and
    antagonists will block the nociceptive effects of serotonin
174
Q
379. Adrenergic receptors are involved in which of the
following functions?
1. Depression
2. Anxiety
3. Arousal
4. Learning
A
  1. Answer: E (All)
175
Q
380. Accurate descriptions of visceral afferent fi bers include
that they
1. travel with sympathetic fi bers
2. are autonomic fi bers
3. have large receptive fi elds
4. do not undergo sensitization
A
  1. Answer: B (1 & 3)
    Explanation:
  2. Visceral afferents generally travel with sympathetic
    fi bers.
  3. They are not autonomic fi bers.
  4. Visceral afferents generally have large, confl uent
    receptive fi elds.
  5. They can be sensitized in response to certain conditions
    (infl ammation).
    Source: Kahn and Desio
176
Q
  1. A neuron contains
  2. a cell body
  3. a dendrite
  4. an axon
  5. a synapse
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
  2. A neuron consists of a cell body (soma)
  3. A neuron contains a dendrites
    - Dendrites are extensions of the cell body.
  4. The axon of one neuron terminates near the cell body or
    dendrites of another neuron.
  5. A synapse is the junction between neurons and serves as
    an important control mechanism for transmission of
    impulses.
177
Q
382. Which pairing(s) is/are correct regarding the typologic
classifi cation of pain?
1. Type I: Nociceptive Pain
2. Type III: Chronic Pain
3. Type III: Neurogenic/neuropathic pain
4. Type I: Idiopathic pain
A
  1. Answer: B (1 & 3)
    Explanation:
    Type I pain is produced in response to defi ned organic
    insult/ trauma as a reaction to primary processes that
    stimulate the nociceptive neuraxis; it is physiologic.
    Type III pain represents a discrete pathologic process in
    which there is peripheral and/ or central sensitization of a
    potential variety of substrates within the nociceptive
    neuraxis; frequently, pain is produced or persists in the
    absence of defi nable organic lesion. It is a neurogenic,
    pathologic process.
    Source: Giordano J, Board Review 2005
178
Q
  1. Which would best be used to clinically assess cognitive
    signs and symptoms of the pain experience?
  2. Beck’s Depression Inventory
  3. Pain Symptoms Index (BAPSI) or Brief Pain Inventory
  4. McGill Pain Questionnaire
  5. Minnesota Multiphasic Inventory (MMPI)
A
  1. Answer: A (1, 2 & 3)
    Explanation:
    Numerous clinical tests are useful in assessing the
    emotional, conscious, and behavioral correlates of
    cognition that result from pain. The BDI, BPI, and MPQ
    have all been shown to have high construct/ content
    validity and replicability, and are reliable evaluative tools
    in clinical pain assessment.
    The MMPI is frequently employed to assess pathologic or
    deviant characteristics of personality in psychiatric and/or
    clinical psychological circumstances. This test is
    sometimes advocated by third party remunerators to
    determine co-morbid confounding factors to patients’
    response/ recovery potential to invasive pain management
    interventions (such as in-dwelling morphine pumps
    and/or DCS); its validity in such circumstances is
    debatable.
    Source: Giordano J, Board Review 2005
179
Q
  1. The precise role(s) of mesencephalic (midbrain) opioids is to:
  2. Inhibit a GABAergic neuraxis
  3. Enhance output of the anterolateral system
  4. Disinhibit bulbospinal anti-nociceptive systems
  5. Act at specifi c dynorphin receptors in the spinal cord
A
  1. Answer: B (1 & 3)
    Explanation:
    Opioids (endorphins and enkephalins) released from
    opioid neurons of the PAG act at mu and delta receptors
    to hyperpolarize tonically inhibitory GABAergic
    interneurons that reduce/ suppress fi ring of
    monoaminergic descending noxious inhibitory control
    systems of the brainstem. Such disinhibition increases
    bulbospinal modulation of noxious afferent input and is a
    fundamental component of centrifugal analgesia.
    Source: Giordano J, Board Review 2005
180
Q
  1. Muscarinic receptors are located in all effector cells
    stimulated by
  2. preganglionic sympathetic neurons
  3. postganglionic parasympathetic neurons
  4. preganglionic parasympathetic neurons
  5. postganglionic cholinergic sympathetic neurons
A
  1. Answer: C (2 & 4)
    Explanation:
    - Muscarinic receptors are located in all effector cells
    stimulated by postganglionic parasympathetic neurons as
    well as postganglionic cholinergic sympathetic neurons.
    - Nicotinic receptors are located in the ganglionic
    synapses between pre- and postganglionic neurons of the sympathetic and parasympathetic nervous system.
    Source: Kahn and Desio
181
Q
  1. Autonomic pain is usually:
  2. Poorly localized
  3. Vague
  4. May be referred pain
  5. Sharp
A
  1. Answer: A (1, 2, & 3)

Source: Nader and Candido Pain Practice. June 2001

182
Q
  1. Physiologic processes involved in nociception include
  2. Transmission
  3. Modulation
  4. Perception
  5. transduction
A
  1. Answer: E (All)
    Explanation:
    Nociception involves four physiologic processes.
  2. Transmission is the propagation of impulses
    throughout the sensory nervous system.
  3. Modulation is the process whereby nociceptive
    transmission is modifi ed through a number of neural
    infl uences
  4. Perception is the fi nal process in which all aspects of
    pain are experienced.
  5. Transduction is the process whereby noxious stimuli
    are translated into electrical activity at the sensory endings
    of nerves.
183
Q
  1. The true statements about cremaster refl ex are.
  2. It is mediated through the ilioinguinal nerve
  3. It is mediated through the genitofemoral nerve
  4. It is evoked by stroking in inner thigh
  5. It results in bilateral elevation of the testicles
A
  1. Answer: A ( 1, 2, & 3)
    Explanation:
    1, 2. The innervation for cremaster refl ex is through the L1
    and L2 segments (ilionguinal and genitofemoral
    nerves).
  2. Stroking the skin on the upper, inner aspect of the thigh
    elicits the cremaster refl ex. The response consists of a
    contraction of the cremasteric muscle, with ipsilateral
    elevation of the testicle
184
Q
  1. True statements about Histamine include that
  2. It causes edema
  3. It causes activation of nociceptors
  4. It causes vasodilation
  5. It is released from injured cells
A
  1. Answer: E (All)
    Explanation:
    Histamine is released from injured cells and from mast
    cells stimulated by substance P.
    It causes activation of nociceptors, vasodilation, and
    edema.
185
Q
  1. True statements about NMDA receptors are:
  2. The pharmacology of central sensitization has shown
    that the N-methyl-d-aspartate (NMDA) receptors are
    involved
  3. Interventions that prevent the establishment of central
    sensitization are considered as preemptive analgesia
  4. Co-administration of NMDA receptor antagonist with
    an opioid may prevent central sensitization
  5. Co-administration of NMDA receptor antagonist with
    an opioid may enhance opioid-induced anti-nociception
    and may prevent tolerance to opioid analgesia
A
  1. Answer: E (All)
    Explanation:
    Dextromethorphan, the D isomer of the codeine analog of
    levorphanol, has been used clinically as a central
    antitussive drug for more than 40 years. It has weak
    affi nity for the μ-opioid receptor and has a sedative effect.
    Dextromethorphan and its metabolite, dextrorphan, have
    non-competitive NMDA receptor antagonist properties.
  2. The pharmacology of central sensitization has shown
    that the N-methyl-d-aspartate (NMDA) receptors are
    involved.
  3. Interventions that prevent the establishment of central
    sensitization are considered as preemptive analgesia
  4. Co-administration of NMDA receptor antagonist with
    an opioid may prevent central sensitization
  5. Co-administration of NMDA receptor antagonist with
    an opioid may enhance opioid-induced anti-nociception
    and may prevent tolerance to opioid analgesia
186
Q
  1. Which of the following correctly describes effects of low frequency (2 - 4 Hz) electrical stimulation acupuncture?
  2. Generalized
  3. Slow in onset
  4. Cummulative effect
  5. Enkephalin-dependent
A
  1. Answer: E (All)

Source: Helms. Acupuncture Energetics. 1995

187
Q
  1. A surgical incision:
  2. Releases chemical mediators that sensitize nociceptors
  3. Primarily activates A-alpha and A-beta fi bers
  4. Increases general sympathetic tone
  5. Stimulates insulin release
A
  1. Answer: B (1 & 3)
188
Q
  1. The facet joints, in the lumbar spine
  2. permit rotation
  3. comprise two arthrodial joints lined with synovium
  4. allow lateral fl exion or bending in the lordotic curve
  5. lie in a vertical sagittal plane, permitting fl exion and
    extension
A
  1. Answer: C (2 & 4)
    Explanation:
  2. The orientation of the facets determines the direction of
    motion of that spinal segment.
  3. Facet joints comprise two arthrodial joints lined with
    synovium and lubricated with synovial fl uid.
  4. In the thoracic spine, the facets are convex-concave and
    lie in the horizontal plane, permitting lateral fl exing, side
    bending, and rotation about a vertical line.
  5. In the upper lumbar spine, the facets lie in a vertical
    sagittal plane and permit fl exion and extension but
    prevent lateral fl exion or bending in the lordotic curve.
189
Q
  1. Withdrawal refl exes are correctly described by the
    following statements:
  2. They are most often elicited by a stretch stimulus
  3. They are transmitted by pathways that pass directly to anterior motor neurons
  4. They typically take 0.2 to 0.5 s to occur
  5. They are associated with extension of the opposite limb
A
  1. Answer: D (4 Only)
    Explanation:
  2. Withdrawal fl exor refl exes are most often elicited by a
    painful stimulus.
  3. Pathways for eliciting the withdrawal refl ex do not pass
    directly to the anterior motor neurons but instead pass
    fi rst through several interneurons.
  4. Associated with withdrawal of the stimulated limb is
    extension of the opposite limb, which occurs 0.2 to o,5 s
    later and serves to push the body away from the object
    causing the painful stimulus.
  5. Withdrawal refl exes are associated with extension of the
    opposite limb.
    Source: Kahn and Desio
190
Q
395. The abdominal wall is divided into nine imaginary
quadrants, which include
1. left iliac
2. right hypochondriac
3. Epigastric
4. hypergastric
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    - The abdominal wall is divided into nine regions by four
    imaginary lines of which two pass horizontally around the
    body and two vertically. The nine regions include the right
    and left hypochondriac, lumbar, and iliac areas and in the
    midline the epigastric, umbilical, and hypogastric areas.
    - The upper horizontal line (transpyloric plane) lies
    between the suprasternal notch and the symphysis pubis.
    - The lower line (transtubercular plane) lies at the top of
    the crests of the iliac bones.
    - Two vertical lines (one on each side of the body) descend
    from the cartilages of the 8th rib to the center of the
    inguinal ligament.
  2. Left iliac and right iliac
  3. Right and left hypochondriac
  4. Midline epigastric
  5. There is no hypergastric quadrant(s)
191
Q
  1. Which of the following are extradural lesions that can
    cause radicular pain?
  2. Herniated nucleus pulposus
  3. Lumbar intraspinal facet joint synovial cyst
  4. Epidural abscess
  5. Tarlov cyst
A
  1. Answer: E (All)

Source: (Bonica, 3rd Ed., page 1566)

192
Q
  1. Hyperalgesia is defi ned as an increased sensitivity to
    a normally painful stimuli. Which of the following
    statements are true regarding primary and secondary
    hyperalgesia:
  2. Primary hyperalgesia is caused by sensitization of
    C–fi bers and occurs immediately within the area of
    the injury.
  3. Secondary hyperalgesia is caused by sensitization of
    dorsal horn neurons and occurs in the undamaged area
    surrounding the injury.
  4. Secondary hyperalgesia is driven mainly by increased
    excitability of central neurons via activated NMDA
    receptors
  5. Intrathecal NMDA antagonists block primary but not
    secondary hyperalgesia.
A
  1. Answer: A ( 1, 2, & 3)
    Explanation:
    Reference:
    Yaksh, Tony in Waldman, Interventional Pain
    Management, Second Edition; Chapter 2, pp. 26-27.
    Bonica’s Management of Pain, Third Edition, Chapter 3,
    Spinal Mechanisms and their Modulation.
    The hallmarks of neuropathic pain are chronic allodynia
    and hyperalgesia. Allodynia is defi ned as pain resulting
    from a stimulus that ordinarily does not elicit a painful
    response (eg. light touch). Hyperalgesia is defi ned as an
    increased sensitivity to a normally painful stimulus. There
    are two types of hyperalgesia which are triggered by
    different neural mechanisms.
  2. Primary hyperalgesia occurs at the site of injury, for
    instance within the confi ned area of capsaicin application.
    - It refl ects sensitization of peripheral nociceptors and
    involves altered physiology and pharmacology of the
    sensory nociceptive terminals to produce a leftward shift
    in the stimulus and response curve for activation.
    - It is triggered by infl ammatory mediators, persisting
    noxious stimuli, or both, and is characterized by lowered
    threshold, increased rate of action potentials, spontaneous
    activity and increased pain sensation to supra-threshold
    stimuli.
  3. Secondary hyperalgesia occurs in the area surrounding
    the area of injured tissue and refl ects the process of central
    sensitization that forms the basis for many types of
    pathological pain.
  4. Secondary hyperalgesia is driven mainly by increased
    excitability of central neurons via activated NMDA
    receptors.
  5. Intrathecal application of NMDA receptor antagonists
    do not attenuate the initial hyperalgesia response to
    capsaicin application (primary hyperalgesia) but the
    secondary delayed pain and sensitivity outside the region
    of injured tissue (secondary hyperalgesia) is substantially
    reduced if the NMDA antagonist is administered prior to
    the initial pain stimulus.
    Source: Schultz D, Board Review 2004
193
Q
  1. True statements regarding substance P include that it
  2. is synthesized in the dorsal root ganglia
  3. is released by stimulation of primary afferent nociceptors
  4. is transported to peripheral and central terminals
  5. inhibits the release of histamine
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
  2. Substance P is synthesized in the neuronal cell bodies in
    the dorsal root ganglia.
  3. Substance is released on stimulation of primary afferent
    nociceptors and causes vasodilation and edema.
  4. It is transported to peripheral and central terminals,
    where it is stored in vesicles.
  5. Substance P causes release of histamine from mast cells,
    resulting in further vasodilation and edema.
194
Q
  1. Statements that correctly describe mechanothermal
    nociceptors include
  2. They are the most common type of nociceptors
  3. They activate both A-delta and C fi bers
  4. They respond to both noxious mechanical and thermal
    stimuli
  5. They may also be referred to as C-polymodal nociceptors
A
  1. Answer: E (All)
    Explanation:
  2. The most common nociceptor appears to be the
    cutaneous mechanothermal nociceptor, which responds to
    noxious mechanical and thermal stimuli.
    The most common nociceptor in humans appears to be
    the C-fi ber mechanothermal nociceptor, which responds
    to mechanical, thermal, and chemical stimuli.
  3. Cutaneous mechanothermal nociceptors activate both
    A-delta and C fi bers.
  4. Modality-specifi c (e.g., heat) nociceptors exist, but the
    majority appear to respond to more than one noxious
    stimulus.
  5. They may also be referred to as C-polymodal
    nociceptors
195
Q
  1. Chronic hyperglycemia from excessive glucose
    administration during parenteral hyperalimentation
    causes
  2. Retinal degeneration
  3. Depression of granulocyte function
  4. Inhibition of platelet aggregation
  5. Hypercarbia
A
  1. Answer: D (4 Only)
196
Q
  1. Which of the following are cardial features of mania?
  2. Insomnia
  3. Distractibility
  4. Flight of ideas
  5. Low self-esteem
A
  1. Answer: A
    Explanation:
    The diagnosis of manic episodes is established by the
    presence of irritability or euphoria associated with 3
    (euphoria) or 4 (irritability) of the 7 cardial symptoms of
    mania. The cardial symptoms of mania are distractibility,
    insomnia, grandiosity, fl ight of ideas, increased activities,
    pressured speech, and thoughtlessness.
    Source: Laxmaiah Manchikanti, MD
197
Q
  1. During muscle testing, extension of the quadriceps is
    primarily innervated by all of the ` following:
  2. L2
  3. L3
  4. L4
  5. L1
A
  1. Answer: A (1, 2, & 3)
    Source: Hoppenfeld S. Physical Examination of the Spine
    and Extremities. Appleton-Centry-Cross/Norwalk, CT
    p.189.
198
Q
  1. True statements concerning the oculocardiac refl ex
    include:
  2. It is more likely to occur in a patient with hypercarbia
    than in a patient with normocarbia
  3. It is not seen during operative procedures on an empty
    orbit
  4. It is afferent limb is the trigeminal nerve
  5. It does not occur in the awake patient
A
  1. Answer: B (1 & 3)
199
Q
  1. Receptor types that mediate analgesia include
  2. Delta
  3. kappa
  4. mu-1
  5. mu-2
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
  2. Spinal analgesia is mediated by the delta and kappa
    receptors.
    Delta-receptor activation results in spinal analgesia
    without sedation or respiratory depression.
    The delta-receptor ligand(D-ala, D-leu enkephalin;DADL)
    has been found to be fi ve times more potent than morphine ( a mu-receptor agonist) when given
    intrathecally.
  3. Kappa-receptor activation results in spinal analgesia and
    sedation without respiratory depression.
  4. Activation of mu-1 receptors has analgesic effects
    (mostly supraspinal, though some mu-1 receptors are
    found in the spinal cord).
  5. Activation of mu-2 receptors produces respiratory
    depression, bradycardia, and depression of GI motility.
200
Q
  1. The true statements regarding the termination of the Cfi
    ber primary afferents in the spinal cord are.
  2. C fi bers collateralize into the tract of Lissauer
  3. C fi bers enter mostly medial to the A-beta fi bers in the
    dorsal root entry zone
  4. C fi bers project rostrally and caudally in the tract of
    Lissauer
  5. No C fi bers exists within the ventral nerve roots
A
  1. Answer: B (1 & 3)
    Explanation:
    As small afferent axons (C and A-delta) enter the spinal
    cord, they are displaced lateral to the A-beta fi bers (from
    muscle spindles and proprioceptive afferents) and
    trifurcate in the tract of Lissauer at the level of entry and
    with projections rostrally and caudally.
    Unmyelinated C fi bers arising from the dorsal root
    ganglion cells also send projections into the ventral roots,
    which accounts for pain sensation that can occur with
    ventral root stimulation.
201
Q
  1. The recurrent laryngeal nerve supplies motor function to the following intrinsic muscles of the larynx
  2. sternothyroid
  3. sternohyoid
  4. thyrohyoid
  5. cricoarytenoid
A
  1. Answer: E (All)
    Explanation:
    Below the level of the vocal cords the larynx and trachea
    are innervated by the recurrent laryngeal branch of the
    vagus nerve.
    The recurrent laryngeal nerve not only provides sensation
    to the structures below the level of the cords, it also
    supplies motor function to all the intrinsic muscles of the
    larynx except the cricothyroid muscle.
    Bilateral blockade of the recurrent laryngeal nerve will
    result in loss of phonation as well as an inability to close
    the glottis.
202
Q
  1. The diameter and conduction velocity of the A-delta
    fi bers, which transmit temperature sensation and sharp
    pain are as follows
  2. 20 microns (m), 5 meters per second (m/s)
  3. 20 m, 100 m/s
  4. 4 m, 20 m/s
  5. 4m, 5 m/s
A
  1. Answer: B (1 & 3)
    Explanation:
    A-alpha fi bers provide large motor function and
    proprioception and are responsible for refl ex activity.
    A-alpha, -beta, and –gamma myelinated fi bers are 20 m in
    diameter. They have a conduction velocity of 100 m/s.
    A-beta fi bers are responsible for small motor function,
    touch, and pressure.
    A-gamma fi bers provide muscle tone via innervation of
    the muscle spindle fi bers.
    A-delta fi bers are myelinated fi bers of 4 m in diameter that
    conduct impulses at 5m/s. They transmit temperature
    sensation, sharp pain, and possibly touch.
    C fi bers are unmyelinated fi bers 0.5 to 1.0m with a conduction velocity of 1.2m/s. They transmit dull pain,
    temperature, and touch.
203
Q
408. The following ganglia transmit purely sympathetic
impulses.
1. Stellate
2. Otic
3. Superior cervical ganglion
4. sphenopalatine
A
  1. Answer: B (1 & 3)
    Explanation:
  2. The stellate ganglion is another term for the inferior
    cervical ganglion, which lies behind the subclavian artery,
    near the origin of the vertebral artery at the level of the
    seventh cervical vertebra. It is sometimes fused with the
    fi rst thoracic ganglion.
    2, 4. Autonomic ganglia include the ciliary, sphenopalatine,
    otic, and submaxillary ganglia, which are situated in a
    relation to the respective cranial nerves (III, VII, and IX).
    Each ganglion receives sympathetic postganglionic
    fi bers, parasympathetic preganglionic fi bers, and sensory
    fi bers.
  3. The superior, middle, intermediate, and inferior ganglia
    compose the sympathetic chain within the cervical region.
    Source: Kahn and Desio
204
Q
  1. The difference between a plexus and ganglion include
    the following
  2. A plexus refers to prevertebral ganglia only
  3. A plexus refers to a site of synaptic connections specifi c
    to the sympathetic system
  4. A plexus may be either sympathetic or para-sympathetic
  5. A plexus refers to ganglia and axons (sympathetic and
    parasympathetic) in a defi ned anatomic location
A
  1. Answer: D (4 Only)
    Explanation:
    1, 2, 3. A ganglion refers to a site of synaptic connections
    specifi c to the sympathetic or parasympathetic systems.
  2. Plexus refers to a number of ganglia and axons
    (sympathetic and parasympathetic, as well as visceral
    afferent) converging in a well-defi ned anatomic location.
205
Q
  1. Clinical situation associated with an increase in
    parasympathetic activity include
  2. Manipulation of the carotid sinus
  3. Intestinal insuffl ation during colonoscopy
  4. Traction of superior oblique muscle during strabismus
    surgery
  5. Caudal anesthesia for excision of a pilonidal cyst
A
  1. Answer: E (All)
206
Q
  1. A-beta fi ber terminal remodeling:
  2. Produces projections to laminae III, V, VI and VII.
  3. Lamina II projections activate nociceptive-specifi c and
    wide dynamic range neurons
  4. Can produce analgesia via activation of the medial lemniscal pathway.
  5. Lamina VII projections can directly engage intermediolateral sympathetic nervous system pre-ganglionic neurons.
A
  1. Answer: C-2and4
    Explanation:
    Reference
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasiticity. Also Bonica’s
    Management of Pain, 3rd Ed: Ch4. Spinal mechanisms and
    modulation. Chronic neuropathic pain can induce plastic,
    genotypic changes in a-beta mechanoreceptors that
    promote phenotypic remodeling of a-beta terminal
    projections within the superfi cial dorsal horn. A-beta
    projections “migrate” into lamina II to activate nociceptive
    specifi c and wide dynamic range neurons to produce
    mechanical hyperalgesia. Increased penetrance to lamina
    VII can directly engage sympathetic preganglionic neurons
    of the intramedial lateral zone to increase sympathetic
    outfl ow and contribute to the cyclisity of SMP. Such
    remodeling in the synaptic fi elds of a-beta
    mechanoreceptors decreased input to second order wide
    dynamic mechanospecifi c neurons that comprise the
    dorsal column/medial lemniscal pathway. This can lead to
    a change in mechanosensation and decrease in dorsal
    columnar inhibition of even mild noxious input.
    Source: Giordano J, Board Review 2005
207
Q
  1. Diffi culties in evaluating sympathetically mediated pain
    include:
  2. Controlling the thermal testing environment when
    conducting topical thermometric evaluations.
  3. Apparent need for repeated assessments to enhance
    sensitivity
  4. Direct correlation of sensitivity to diagnostic accuracy
  5. Pain quality and intensity is frequently not refl ected in
    quantitative assessments
A
  1. Answer: E- all
    Explanation:
    Reference
    Lecture notes. Sympathetically mediated pain may be
    diffi cult to evaluate based solely upon results of single
    technologic diagnostic tests. Characteristically, thermal
    metric evaluation is coupled with quantitative sensory
    testing, axon refl ex evaluation, Doppler, fl owmetry and
    correlated with patient narrative, history and physical
    exam. The need for narrative/history emphasizes the
    discrepant characteristics of qualitative (subjective)
    aspects of SMP and quantitative variables.
    Source: Giordano J, Board Review 2005
208
Q
  1. Neurogenic infl ammation:
  2. is mediated, in part by antidromically released Substance
    P.
  3. causes depletive desensitization of C-fi ber afferents
  4. can produce central hyperalgesia.
  5. is not at all reliant on cycloxygenase-derived products
    for initiation or maintenance
A
  1. Answer: B-1and3
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch 3. Peripheral
    pain mechanisms and nociceptive plasiticity. Initial tissue
    insult can induce the arachidonic acid cascade, to produce
    cycloxygenase derived prostaglandin E2 that activates
    peripheral C-fi bers via effects at a prostenoid receptor on
    C-fi ber terminals. The activation of C-fi bers can cause
    antidromic release of Substance P which acts as a potent
    vasodilator thereby inducing extravasation of pronocicepted
    mediators and subsequent
    reactivation/sensitization of C-fi bers. Prolonged C-fi ber
    activation/sensitization can produce primary hyperalgesia.
    Continued C-fi ber-evoked activation of second order
    spinal afferents can produce central (secondary)
    hyperalgesia.
    Source: Giordano J, Board Review 2005
209
Q
  1. The following statements are true regarding sympathetic
    modulation of nociceptive transmission
  2. Acute sympathetic nervous function can engage limbic
    mechanisms to produce attentional analgesia.
  3. Sympathetic activation can produce a relatively short
    term modulation against nociceptive pain.
  4. Sympathetic activation can induce release of adrenal
    opioids to modulate nociceptive pain.
  5. Long term stress can produce durable inhibition of
    neuropathic pain
A
  1. Answer: A-1, 2 and 3
    Explanation:
    Reference:
    Bonica’s Management of Pain, 3rd Ed: Ch4. Spinal
    mechanisms and modulation. Yaksh T In: Waldman,
    interventional pain management, 2nd Ed, Ch. 2. Acute
    sympathetic activation is a principle substrate of stress
    induced analgesia (SIA). SIA involves both the release of
    adrenal opioids as well as engagement of multiple nonopioid
    peptide and non-peptide brain mechanisms
    that can produce peripheral and central (“attentional”
    analgesia against nociceptive pain. Long term stress and
    chronic sympathetic activatin is pain promotional and
    certainly not modulatory of neuropathic pain.
    Source: Giordano J, Board Review 2005
210
Q
  1. A patient undergoes a mid-thoracic ventrolateral
    cordotomy for control of intractable pain. The following
    statements are true regarding effects of this procedure:
  2. The patient would likely experience loss of pain sensation
    on the contralateral side several segments below
    the lesion.
  3. Light touch sensation would be lost on the ipsilateral
    side at the level of the lesion and below.
  4. Temperature (hot and cold) sensation would be lost
    on the contralateral side several segments below the
    lesion.
  5. The pain relieving effects of the lesion would likely be
    complete and permanent.
A
  1. Answer: B (1 & 3)
    Explanation:
    Reference:
    Yaksh, Tony in Waldman, Interventional Pain
    Management, Second Edition; Chapter 2,
    Bonica’s Management of Pain, Third Edition, Chapter 4,
    Spinal Mechanisms and their Modulation
    If the spinal cord is completely transected, all sensory and
    motor functions distal to the transaction are blocked.If the
    spinal cord is transected only on a single side, the Brown-
    Sequard syndrome occurs:
    - Loss of motor function ipsilateral to the lesion at all
    levels below the lesion.
    Pain and temperature sensation is lost on the contralateral
    side 2 to 6 dermatomes below the lesion.
    - Light touch and tactile sensation is lost ipsilateral to the
    lesion at all levels below the lesion.
    This pattern of loss occurs because:
    - Pain and temperature sensation is a crossed neural
    pathway. Pain and temperature fi bers enter the dorsal horn
    through the dorsal root, ascend and descend for several
    segments in Lissauer’s tract in the superfi cial cap of the
    dorsal horn, then enter the dorsal horn, synapse with
    interneurons and move across the cord in the anterior
    commissure to the contralateral side where they ascend in
    the ventrolateral columns (especially the spinothalamic
    tract). Transection of the ventrolateral tract will transect
    pain and temperature fi bers which originate on the
    contralateral side of the cord several segments below the
    lesion.
    - Motor function is not crossed. Motor fi bers stay
    ipsilateral at the cord level so transaction of the one side of
    the cord will cause ipsilateral motor loss below the lesion.
    - Light touch is transmitted by A-beta fi bers which ascend
    ipsilaterally in the dorsal columns. Hemisection of the
    cord will also cause ipsilateral light touch loss below the
    lesion.
  2. With ventrolateral cordotomy, the target is isolated to
    the spinothalamic tract.
    - This tract primarily transmits ascending pain and
    temperature fi bers which originate contralaterally.
    - The expected result would be loss of pain and
    temperature sensation several segments below the lesion
    on the contralateral side with no effect on motor strength
    or tactile sensation.
  3. Light touch and tactile sensation is lost ipsilateral to the
    lesion at all levels below the lesion.
  4. Temperature (hot and cold) sensation would be lost on
    the contralateral side several segments below the lesion.
  5. The pain relieving effects of ventrolateral cordotomy
    are typically incomplete because some nociceptive fi bers
    do not cross and ascend ipsilaterally. The effects are
    typically short-lived with anomalous recovery of pain after
    3-12 months. This suggests that relevance of other pain
    pathways outside of the crossed, spinothalamic path.
    Source: Schultz D, Board Review 2004
211
Q
  1. Somatic pain is usually:
  2. Sharp
  3. Precisely localized
  4. Hurts where the stimulus is
  5. Tends to increase with increasing stimulus intensity
A
  1. Answer: E (All)

Source: Nader and Candido – Pain Practice. June 2001

212
Q
  1. Sensory receptors include
  2. mechanoreceptors
  3. electromagnetic receptors
  4. Thermoreceptors
  5. Nociceptors
A
  1. Answer: E (All)
    Explanation:
    The fi ve basic types of sensory receptors are:
  2. Mechanoreceptors, which detect tissue deformation
  3. Electromagnetic receptors, which detect light on the
    retina
  4. Thermoreceptors for cold and warmth
  5. Nociceptors, which detect painful stimuli due to
    physical or chemical damage in tissue
    The fi fth type, chemoreceptors, which detect taste, smell,
    arterial partial pressure of oxygen and carbon dioxide, and
    serum osmolarity.
213
Q
418. Which of the following is a labeled indication for
prescribing CNS stimulants?
1. Chronic pain with thalamic strokes
2. Reversing opioid induced sedation
3. Enhanced alertness for driving
4. Narcolepsy
A
  1. Answer: D (4 Only)

Source: Boswell MV, Board Review 2004

214
Q
  1. Visceral nociception is accurately characterized by the
    following statements.
  2. It typically has a signifi cant autonomic component
  3. It respond to cutting, burning, or crushing stimuli
  4. It is often diffuse and poorly localized
  5. It involves more nociceptors than cutaneous nociception
A
  1. Answer: B (1 & 3)
    Explanation:
    There are signifi cant clinical differences between
    visceral and cutaneous nociception.
    There are relatively fewer nociceptors in the viscera than
    in the skin, and these receptors may have a different
    activation profi le.
    Cutting and burning mesentery, uterine cervix, or other
    organs does not necessarily produce clinical “pain”, but
    traction, distention, or ischemia will produce pain.
    Visceral is often diffuse and poorly localized and often
    has a significant autonomic component.
215
Q
420. Intraspinal opioid infusions became important for pain
relief with the discovery of
1. delta-receptors
2. gamma-receptors
3. beta-receptors
4. mu-receptors
A
  1. Answer: D (4 Only)

Source: Lou Etal. Pain Practice: march 2001

216
Q
  1. The neurogenic pain mediators include all the following:
  2. Calcitonin gene-related peptides
  3. Vasoactive interstital peptides
  4. Substance P
  5. Thromboxane A2
A
  1. Answer: D (4 Only)

Source: Rozen. Pain Practice: SEP 2001

217
Q
  1. The following might be associated with sympathetic
    efferent overactivity.
  2. Cutaneous nociceptive sensitivity
  3. Alteration in piloerection
  4. Alteration in blood fl ow to skin and muscle
  5. Alteration of sweating
A
  1. Answer: E (All)
    Explanation:
    Pain following peripheral nerve damage has long been
    recognized as having a sympathetic component.
  2. It is clear that sympathetic afferents can transmit
    information of a nociceptive nature.
  3. One of the characteristics of this pain is that is
    accompanied by sympathetic efferent overactivity. This
    may be refl ected in alterations in the control of blood fl ow
    to the skin, muscles, and bone in the affected area and
    alterations in piloerection, sweating, and possibly
    cutaneous nociceptive sensitivity.
    Source: Kahn and Desio
218
Q
  1. Mechanically sensitive discs are defi ned as
  2. Pressure between 0-25 PSI
  3. Pressure between 10-35 PSI
  4. Pressure between 25-50 PSI
  5. Pressure between 50-75 PSI
A
  1. Answer: D (4 Only)

Source: Rozen. Pain Practice: SEP 2001

219
Q
424. The following drugs are known to provide NMDA
receptor antagonism
1. dextromethorphan
2. dextrorphan
3. ketamine
4. neostigmine
A
  1. Answer: A (1, 2, & 3 )

Source: Lou Etal. Pain Practice: march 2001

220
Q
  1. The central nervous system consists of
  2. Brain
  3. cranial nerves
  4. spinal cord
  5. spinal nerves
A
  1. Answer: B (1 & 3)
221
Q
  1. G-protein coupled receptor activation produces
    pharmacologic effects by modulation of which of the
    following?
  2. Cyclic AMP
  3. Ionic channels
  4. Phospholipases
  5. Protein kinases
A
  1. Answer: E (All)
    Explanation:
    G-protein receptors are a large (> 100) family of
    membrane spanning receptors that undergo a conformational change with drug-receptor binding which
    in turn causes activation of “G-Proteins” [di- or
    triphospho-guanosine-binding proteins (G-GDP, GGTP)].
    All cells contain G-protein receptors, but the brain
    has the highest concentration and the gut is especially rich.
    G-proteins produce pharmacological effects through their
    control or regulation of membrane-bound, second
    messenger systems such as ion channels, cyclic AMP, or
    phosopholipases (the phosphoinositol turnover system)
    and protein kinases.
    Source: Boswell MV, Board Review 2004
222
Q
  1. Inhibitory neurotransmitters include
  2. glutamic acid
  3. Glycine
  4. substance P
  5. gamma-aminobutyric acid
A
  1. Answer: C (2 & 4)
    Explanation:
  2. Glutamic acid is an excitatory neurotransmitter secreted
    by many of the sensory pathways of the CNS.
  3. Glycine is secreted mainly at synapses in the spinal cord,
    where it functions predominantly as an inhibitory
    neurotransmitter.
  4. Substance P is an excitatory neurotransmitter presumed
    to be released by terminals of pain fi bers in the substantia
    gelatinosa of the spinal cord.
  5. GABA is an inhibitory neurotransmitter secreted by
    neurons in diverse areas of the nervous system including
    the spinal cord, cerebellum, and basal ganglia.
223
Q
  1. Trigeminal neuralgia is characterized by
  2. Unilateral, intense, paroxysmal pain of sudden onset
  3. Diminished sensation in the distribution of the maxillary
    division of the trigeminal nerve
  4. Normal function of the glossopharyngeal nerve
  5. Resolution of symptoms by injection of local anesthetic
    in trigger points
A
  1. Answer: B (1 & 3)
224
Q
  1. Cholinergic neurons in the brain include
  2. Basal forebrain
  3. Medial raphe
  4. Basal ganglia
  5. Locus ceruleus
A
  1. Answer: B (1 & 3)
225
Q
  1. Criteria for neurotransmitters in primary afferent
    nociceptors include
  2. the substance is present in the dorsal horn synapse
  3. the substance is released on noxious stimulation
  4. release of the substance causes the same effect as stimulation
    of the primary effect
  5. injection of the substance causes pain
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    Criteria for proving that a substance is a neurotransmitter
    for a primary afferent nociceptor are:
    (1) presence of the substance in the dorsal horn synapse of
    the primary afferent,
    (2) release of the substance on noxious stimulation,
    (3) the same effect by release of the substance and
    stimulation of the primary afferent, and
    - Blockade of the effect of both the substance and the
    primary afferent by administration of an antagonist.
    Source: Kahn and Desio
226
Q
  1. Each of the following is a function of the facial nerve.
  2. it carries parasympathetic secretory fi bers to the lacrimal
    glands
  3. it is involved in the afferent limb of the orbicularis oculi
    refl ex
  4. it innervates muscles of facial expression
  5. it conveys exteroceptive sensation from the region of
    the eardrum
A
  1. Answer: E (All)
    Explanation:
    1.The facial nerve carries parasympathetic secretory fi bers
    to the salivary and lacrimal glands and to the mucous
    membranes of the oral and nasal cavities.
  2. The facial nerve contributes to the afferent limb of the
    orbicularis oculi refl ex in conjunction with the trigeminal
    nerve.
  3. The facial nerve innervates the muscles of facial
    expression.
  4. The facial nerve conveys various types of sensation, including exteroceptive sensation from the region of the
    ear drum, taste sensation from the anterior two-thirds of
    the tongue, and general visceral sensation from the salivary
    glands and mucosa of the nose and pharynx.
227
Q
  1. The following tracts are primarily involved with
    transmission of pain, temparture and touch
  2. spinocerebellar
  3. fasciculus gracilis
  4. spinothalamic
  5. fasciculus cuneatus
A
  1. Answer: E (All)
    Explanation:
  2. Unconscious sensation is mediated by the
    spinocerebellar tract.
  3. The Fibers associated with proprioception and crude
    touch enter the dorsal horn and ascend ipsilaterally in the
    dorsal columns (fasciculus gracilis and fasciculus
    cuneatus).
  4. The spinothalamic tract subserves the sensations of pain
    and temperature.
  5. The Fibers associated with proprioception and crude
    touch enter the dorsal horn and ascend ipsilaterally in the
    dorsal columns (fasciculus gracilis and fasciculus
    cuneatus).
228
Q
  1. Administration of substance P causes the following.
  2. Plasma extravasation
  3. Pain on local injection
  4. Neurogenic infl ammation
  5. Activation of nociceptors
A
  1. Answer: B (1 & 3)
    Explanation:
  2. Administration of substance P provokes plasma
    extravasation; other peptides do not produce
    extravasation.despite its role in the initiating and
    augmentation of neurogenic infl ammation.
  3. Substance P does not produce pain on local injection.
  4. Substance P causes neurogenic infl ammation.
  5. Substance P does not activate nociceptors.
229
Q
434. Descending inhibitory pathways typically involve the
following neurochemical mechanisms.
1. Noradrenergic
2. Enkephalinergic
3. Serotonergic
4. Cholinergic
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    Centrifugal control of nociceptive transmission through
    the dorsal horn arises from a variety of structures that
    project descending inhibitory pathways.
    1, 2, 3. The pathways descending from these areas
    primarily involve noradrenergic, serotonergic, and
    enkephalinergic mechanisms. However, other mechanisms
    might also be involved.
    Source: Kahn and Desio
230
Q
  1. Muscle-stretch refl exes are diminished or absent in each of the following conditions:
  2. deep sedation
  3. deep coma
  4. hypothyroidism
  5. strychnine poisoning
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    Diminution of the reflexes usually results from an
    interference with the conduction of an impulse through
    the reflex arc. Absence indicates a break in the reflex arc.
    1, 2. The muscle-stretch reflexes may be either diminished
    or absent in deep coma, narcosis, deep sedation, and often
    in deep sleep.
  2. Hypothyroidism and severe toxemias result in
    diminished or lost reflexes.
  3. Muscle-stretch refl exes are typically increased with
    pyramidal system lesions, early stages of coma and
    anesthesia, tetany, tetanus, and strychnine poisoning.
    Source: Kahn and Desio
231
Q
  1. Spondylolisthesis refers to:
  2. Fracture of both pars interarticularii
  3. Fracture of one pars interarticularii
  4. The slip of the cephalad vertebral body posteriorly with
    respect to the caudad vertebral body
  5. A slip of the cephalad vertebral body anteriorly with
    respect to the caudad vertebral body
A
  1. Answer: D
    Explanation:
    The term spondylolisthesis occurs when the cephalad
    vertebral body slip forward with respect to the inferior
    vertebral body. This slip can be graded in terms of
    percentage or grade (grade 1 76%). Etiologies include a
    bilateral pars defect (spondylolysis), degenerative changes
    in the facet joint, disc incompetence, cancer, infection,
    post-surgical (wide decompression). Nonetheless,
    spondylolisthesis refers to the slip and not the etiology.
    Not all cases of bilateral pars defects will go on to develop
    spondylolisthesis.
    Unilateral pars defects are unlikely to lead to slip.
    Retrolisthesis, which can occur with disc incompetence
    and segmental instability, refers to posterior slippage of
    the superior vertebral body with respect to the inferior
    vertebral body. Segmental instability represents a
    condition where a functional spinal unit (2 VBs and the
    intervertebral disc) are hyper-mobile. At L5-S1, this
    represents >11-15 degrees of motion compared to other
    segment or >5 mm of anterior translation.
    Source: Shah RV, Board Review 2006
232
Q
437. The sequence of events involved in neurogenic
infl ammation includes
1. spreading vasodilation
2. sensitization of C-PMNs
3. Edema
4. secondary hyperalgesia
A
  1. Answer: E (All)
    Explanation:
    After injury just outside their receptive fi elds, C-PMNs
    become sensitized and develop spontaneous
    depolarization.
    1, 2, 3. This activity of C-PMNs in areas of undamaged
    tissue causes spreading vasodilation, edema, and further
    sensitization of other C-PMNs within adjacent receptive
    fi leds. This sequence of events has been termed neurogenic
    infl ammation because of its similarity to the infl ammatory
    process.
  2. Secondary hyperalgesia depends on activity in
    unmyelinated primary afferents with sensitization of CPMNs.
233
Q
  1. Which of the following correctly describe an agonist
    drug?
  2. Produces an effect by inducing conformation change
  3. May displace an endogenous ligand from the receptor
  4. Receptor interaction mediated by weak molecular
    forces
  5. Binds by covalent forces to the receptor
A
  1. Answer: A ( 1, 2, & 3)

Source: Boswell MV, Board Review 2004

234
Q
  1. True statements regarding C fi bers include that they
  2. are unmyelinated
  3. are mostly nociceptive
  4. respond to mechanical, thermal, and chemical stimuli
  5. make up a small proportion of fi bers in a peripheral
    nerve
A
  1. Answer: A (1, 2, & 3 )
235
Q
  1. C-polymodal nociceptors (C-PMNs)
  2. have large receptive fi elds
  3. do not undergo sensitization
  4. are involved with secondary hyperalgesia
  5. respond only to mechanical and thermal stimulation
A
  1. Answer: B (1 & 3)
    Explanation:
  2. The receptive fi eld for a C-PMN may be quite large (up
    to 17mm2).
  3. C-PMNs become sensitized after repeated noxious
    stimulation and may develop an ongoing discharge.
  4. Secondary hyperlgesia depends on activity in
    unmyelinated primary afferents with sensitization of CPMNs.
  5. Respond to mechanical, thermal and chemical stimuli.
    (DR M CHECK)
    Source: Kahn and Desio
236
Q
  1. Pain caused by a brief noxious stimulus and experienced
    as brief and sharp (fi rst pain)
  2. can be blocked by applying local anesthetic
  3. can be blocked by applying pressure
  4. is mediated by C-PMNs
  5. can occur in response to a thermal stimulus
A
  1. Answer: C (2 & 4)
    Explanation:
    Application of a brief noxious stimulus will initially be
    experienced as a brief, sharp pain (fi rst pain).
    A more prolonged, dull sensation (second pain) follows
    after a short lull. Application of pressure will block fi rst
    pain.
  2. Application of local anesthetics will block second pain.
  3. First pain is preferentially blocked by pressure.
  4. First pain is mediated by the A-delta mechanothermal
    nociceptor.
  5. First pain can occur in response to a thermal stimulus.
    Source: Kahn and Desio
237
Q
  1. True statements about A-delta fi bers include the following
    :
  2. They are myelinated
  3. They do not respond to mechanical stimulation
  4. They conduct impulses at a rate of 20m/s
  5. They are also called low-threshold mechano-receptors
A
  1. Answer: B (1 & 3)
    Explanation:
  2. They are myelinated.
  3. They respond to mechanical stimulation.
  4. Myelinated fi bers activated by noxious stimuli generally
    conduct in the A-delta range, about 20 m/s.
  5. A-delta fi bers are called high-threshold
    mechanoreceptors.
  6. Answer: A (1, 2, & 3 )
238
Q
  1. The class of compounds considered prostanoids include:
  2. Prostacyclins
  3. Thromboxanes
  4. Prostaglandins
  5. leukotrienes
A
  1. Answer: A (1, 2, & 3 )
    Explanation:
    - The prostanoids are the arachidonic acid metabolites of the cyclooxygenase pathway that comprise the
    thromboxanes, prostacyclins, and prostaglandins.
    - The eicosanoids are the arachidonic acid metabolites of
    the lipoxygenase pathway including 5-
    hydroxyeicosatetraenoic acid (5-HETE) and the
    leukotrienes.
239
Q
  1. Sensitization of high-threshold mechanoreceptors
  2. is associated with a higher threshold to thermal stimulation
  3. requires repeated stimulation
  4. is associated with a lower threshold to mechanical
    stimulation
  5. results in increased frequency of discharge
A
  1. Answer: C (2 & 4)
    Explanation:
  2. After repeated thermal stimulation, HTMs will become
    more sensitive (achieve a lower threshold to thermal
    stimulation) and will increase their frequency of discharge.
    This process is known as sensitization.
  3. High-threshold mechanoreceptors (HTMs) do not fi re
    in response to thermal stimulation unless stimuli are
    applied repeatedly.
  4. The threshold for mechanical stimulation is unchanged
    by this process.
  5. Sensitization of high-threshold mechanoreceptors,
    results in increased frequency of discharge.
240
Q
  1. True statements about characteristics of skin injury are:
  2. Local edema
  3. Intense vasoconstriction
  4. Secondary vasodilation in adjacent areas
  5. Increased threshold for nonnoxious stimuli
A
  1. Answer: B (1 & 3)
    Explanation:
    The characteristic sequence of events following a skin
    injury is known as the triple response:
  2. Local edema (wheal).
  3. Intense vasodilation.
  4. Secondary vasodilation spreading to adjacent regions
    (fl are).
  5. The subject will also note a decreased threshold to
    noxious stimuli and increased pain in response to noxious
    stimulation (primary hyperalgesia) in the injured area.