OS 202 B Samplex 2014 A

Question 1

Which of the following statements is/are true of generator potentials? All generator potentials are:

A. Produced by changes in membrane potential
through opening of ligand gated channels
B. Depolarizing currents
C. Local and graded potentials
D. All of the above statements are true

Answer 1

C

Question 2

Which of the following somatic sensations may be
reflexively mediate

A. Pressure
B. Proprioception
C. Two-point discrimination
D. Vibration

Answer 2

B

Question 3

What encodes the intensity of a sensation?

A. Spatial and temporal patterns of activation of
receptors
B. Size of the receptive field
C. Amplitude of the action potential
D. Lateral inhibition in the higher order neuron

Answer 3

A

Question 4

The following sensory receptors respond to low
threshold mechanical stimulation EXCEPT

A. Meissner’s corpuscle
B. Merkel’s disk
C. Ruffini’s endings
D. Free nerve endings

Answer 4

D

Question 5

Two-point discrimination is best perceived at the
finger tips because

A. There is a high density of receptors in the area.
B. The receptors are innervated by the fastest
conducting A fibers
C. There is less overlapping of sensory units
D. Receptors are rapidly adapting.

Answer 5

A

Question 6

Which of the following statements is true of lateral
inhibition in sensory systems? Lateral inhibition:

A. modulates perception of intensity
B. defines the type of sensory modality
C. sharpens discrimination of stimuli
D. determines the duration of the stimuli

Answer 6

C

Question 7

What would be an evidence that parallel processing of various sensory information of a given modality exists in the nervous system?

A. Specific sensory pathways are discrete from the sense organ to the cortex.
B. Excitation of any region along a sensory pathway always gives the same sensation.
C. The phenomenon of phantom limb is an evidence of parallel processing.
D. A discrete lesion in the temporal lobe produces deafness for low tones but not for high tones.

Answer 7

D

Question 8

Sensory afferent input to the amygdala which processes the affect of a given sensation is through which sensory pathway?

A. Paleospinothalamic tract
B. Spinoreticular tract
C. Spinomesencephalic tract
D. Neospinothalamic tract

Answer 8

C

Question 9

Which of the following receptors signal changes in muscle activity?

A. Golgi tendon organs
B. Nuclear chain fibers
C. Nuclear bag fibers
D. AOTA

Answer 9

D

Question 10

Which of the following statements is/are true of muscle spindles?

A. They detect changes in both muscle length and tension
B. They are innervated by both gamma and alpha motor neurons.
C. Activation of muscle spindles increases muscle tension to oppose the stretch.
D. All of the above statements are true.

Answer 10

C

Question 11

During withdrawal reflex, the following sensory receptors are activated

A. Proprioceptors
B. Bare nerve endings
C. Muscle spindles
D. Only a and b
E. AOTA

Answer 11

E

Question 12

The terminals of nociceptive afferents when stimulated release which of the following neurotransmitters?

A. Substance P
B. Glutamate
C. Enkephalins
D. Only and b
D. AOTA

Answer 12

D

Question 13

Which type of nerve fibers innervate the polymodal nociceptors?

A. A-alpha fibers
B. A-beta fibers
C. A-delta fibers
D. C fibers

Answer 13

D

Question 14

A medical student observed that stimulating the neurons located in the midline of the medulla attenuates pain sensation in animals. Which of the following mechanisms could explain this observation?

A. Serotonin was released which inhibited the dorsal horn cells.
B. Noradrenaline was released which inhibited the dorsal horn cells.
C. Enkephalin was released which inhibited the dorsal horn cells.
D. Release of substance P from the axons of the dorsal root ganglion was inhibited.

Answer 14

A

Question 15

Armed with knowledge of neurophysiology, what type of drug or substance would you develop that can relieve pain?

A. a drug that inhibits synaptic calcium channels
B. a drug that inhibits sodium channels
C. a drug that blocks glutamate receptors
D. any of the above

Answer 15

D

Question 16

Which of the following mechanisms explain why visceral pain tends to be vague and poorly localized than somatic pain?

A. There are more C fibers in visceral afferents than A delta.
B. There is less overlapping of receptive fields in the viscera.
C. There are more visceral afferents that cover a wide area.
D. Visceral afferents demonstrate more converging synaptic pattern than somatic afferents.

Answer 16

A

Question 17

Which of the following statements is true of hyperopic individuals?

A. The image formed falls in front of the retina.
B. They have sharp vision for near but blurred vision far.
C. They require some degree of accommodation at all times to bring the image onto the retina.
D. To correct the refractive error, the use of concave lens is prescribed.

Answer 17

C

Question 18

The following events that occur in the rods in response to light are listed below in random sequence:

1. decrease in intracellular cGMP
2. activation of transducin
3. closure of sodium channels
4. conformational changes in rhodopsin
5. decreased release of glutamate from the terminal ends of the rods

What is the right sequence in which the above events normally occur?

A. 1,2,3,4,5
B. 1,4,2,5,3
C. 2,4,1,3,5
D. 2,1,4,5,3

Answer 18

C

Question 19

Dark adaptation is best illustrated when one enters a dimly lighted theater. It takes sometime before one gets used in the dark. Which of the following statements is true of dark adaptation?

A. As the eyes become more adapted in the dim, rhodopsin stores diminishes in amount.
B. During dark adaptation, there is a decline in the visual threshold.
C. Dark adaptation takes a shorter period of time than light adaptation.
D. Rods adapt more rapidly than cones

Answer 19

B

Question 20

Stimulation of which of the following fibers give rise to a longer-lasting, burning and pricking pain?

A. A-alpha fibers
B. A-beta fibers
C. A-delta fibers
D. C fibers

Answer 20

D

Question 21

The parvocellar cells process which submodality of the visual sensation?

A. location
B. depth
C. movement
D. color

Answer 21

D

Question 22

What cranial nerves innervate the olfactory epithelium?

A. CN I and V
B. CN I and VII
C. CN I and IX
D. CN I and XII

Answer 22

A

Question 23

What is the function of the odorant binding proteins?

A. They facilitate transport of the odorant through the epithelium.
B. They make the odorant more water soluble.
C. They also act as receptors for the odorants.
D. They are enzyme inducers of the second messenger signal.

Answer 23

A

Question 24

Which taste sensations below utilize direct ion
channel signalling in generating action potentials?

A. sweet
B. salty
C. bitter
D. umami

Answer 24

B

Question 25

Which of the following events is elicited by the mechanical displacement of the cochlear hair cells toward the kinocilium? A. The hair cells on which the cilia are located are hyperpolarized. B. There is an influx of K+ ions through the apical membrane of the cilia. C. There is an influx of Na+ ions through the apical membrane of the cilia. D. There is an efflux of Ca++ ions through the voltage-gated channels in the apical membrane of the cilia.

Answer 25

B

Question 26

Which of the following items are incorrectly paired? A. localization of sound- harmonic vibrations B. loudness of sound- amplitude of sound waves C. pitch of sound- frequency of sound waves D. None of the above

Answer 26

A

Question 27

Which physiologic mechanism/s prevent/s the sound energy from being lost as it travels from air through the liquid compartment of the inner ear? A. high aerial ratio between the tympanic membrane and oval window B. the lever system increases efficiency of sound transmission C. The flexibility of the Reissner’s membrane conserves the energy of the travelling waves. D. All of the above E. Only a and b are correct.

Answer 27

E

Question 28

The following statements are true of the vestibulococular reflex EXCEPT A. It is initiated by impulses from the photoreceptors B. The movement of the eyes is opposite to the head movement C. It can be elicited even under dark illumination. D. It does not require feedback from its receptors to function normally

Answer 28

A

Question 29

Which of the following conditions may give a negative caloric test? A. hypofunction of the vestibular apparatus B. inadequate temperature of the test stimuli C. inappropriate head positioning D. AOTA E. Only a and b will give a negative caloric test.

Answer 29

D

Question 30

Majority of neurons in the somatosensory and special sensory systems are of which polarity? A. unipolar B. pseudounipolar C. bipolar D. multipolar

Answer 30

B

Question 31

Majority of neurons in the central nervous system, as a whole, are which polarity? A. unipolar B. pseudounipolar C. bipolar D. multipolar

Answer 31

D

Question 32

Receptor neurons in the retina and olfactory epithelium are of which polarity? A. unipolar B. pseudounipolar C. bipolar D. multipolar

Answer 32

C

Question 33

The spinal nucleus of the trigeminal nerve is equivalent to the: A. Lissauer’s tract B. dorsal horn of the spinal cord C. anterior horn of the spinal cord D. intermediate horn of the spinal cord

Answer 33

B

Question 34

In the general scheme of the somatic sensory system, the neurons which give rise to ascending fibers that cross the midline are the: A. first-order neuron B. second-order neuron C. third-order neuron D. receptor neuron

Answer 34

B

Question 35

At the level of the cervical spinal cord, the pain fibers from the leg and genitalia within the spinothalamic tract are located a. Most medially b. Most laterally c. Most dorsally d. Most ventrally

Answer 35

B

Question 36

The sensory pathway that ascends uncrossed until the level of the medulla is the: a. Spinothalamic tract b. Posterior column – medial lemniscal tract c. Trigeminothalamic tract d. Gustatory fibers

Answer 36

B

Question 37

Proprioceptive fibers from the leg terminate in the a. Nucleus gracilis b. Nucleus cuneatus c. Principal nucleus d. Spinal nucleus of V

Answer 37

A

Question 38

Which is not a pain-sensitive structure in the head? a. Middle meningeal artery b. Superior saggital venous sinus c. Occipital lobe d. Periosteum of the skull

Answer 38

C

Question 39

Which of the following does not transmit pain impulses within the head and neck? a. Trigeminal nerve b. Vestibulocochlear nerve c. Glossopharyngeal nerve d. None of the above

Answer 39

B

Question 40

Tooth pulp is innervated by which nerves? a. Facial neves b. Alveolar nerves c. Buccal nerves d. Dentic nerves

Answer 40

B

Question 41

Pain fibers receiving the head will eventually terminated in the thalamus, specifically in: a. Lateral inferior nucleus b. Ventroposterolateral nucleus c. Ventroposteromedial nucleus d. Mediodorsal nucleus

Answer 41

C

Question 42

The cranial nerve nucleus that is analogous to the cuneate and gracile nuclei is the a. Spinal nucleus b. Principal nucleus c. Ambiguous nucleus d. Solitary nucleus

Answer 42

B

Question 43

Loss of proprioception on the left with loss of pain sensation on the right below the level of the umbilicus is suggestive of a lesion in the: a. Right hemicord, T6 level b. Left hemicord, T6 level c. Right hemicord, T10 level d. Left hemicord, T10 level

Answer 43

D

Question 44

Fibers from the _______ half of each retina decussate at the optic chiasm. a. Nasal b. Temporal c. Superior d. Inferior

Answer 44

A

Question 45

Fibers from the _______ half of each retina remain uncrossed at the optic chiasm. a. Nasal b. Temporal c. Superior d. Inferior

Answer 45

B

Question 46

Due to refraction of light, the superior halves of the retinas see the: a. Upper half of the image b. Bottom half of the image c. Nasal half of the image d. Temporal half of the image

Answer 46

B

Question 47

Majority of the fibers of the optic tracts will synapse on which nucleus of the thalamus a. Ventroposteromedial nucleus b. Ventroposterolateral nucleus c. Medial geniculate nucleus d. Lateral geniculate nucleus

Answer 47

D

Question 48

Sparing of the papillary light reflex, despite bilateral occipital cortex lesions, is because some optic tract fibers bypass the thalamus and terminate in: a. Superior colliculus b. Inferior colliculus c. Edinger-Westphal nuclei d. Line of Gennari

Answer 48

C

Question 49

Right superior quadrantanopia is a sign of lesion in the: a. Left optic nerve b. Left optic tract c. Left parietal optic radiations d. Left temporal optic radiations

Answer 49

D

Question 50

Transection of the decussating fibers at the optic chiasm result in: a. Bilateral blindness b. Bilateral hemianopia c. Bitemporal hemianopia d. Monocular blindness

Answer 50

C

Question 51

The second-order neuron in the auditory pathway is located in the a. Cochlear nucleus b. Inferior colliculus c. Medial geniculate body d. Spiral ganglion

Answer 51

A

Question 52

Taste fibers from cranial nerves VII, IX and X terminate in the a. Rostral half of the nucleus solitarius b. Caudal half of the nucleus solitarius c. Nucleus ambiguus d. Spinal nucleus

Answer 52

A

Question 53

The second-order neuron in the olfactory pathway is the a. Bipolar olfactory neuron b. Mitral cell c. Thalamic M cell d. Ganglion cell

Answer 53

B

Question 54

Profound loss of sensation (pain and light touch) over the left side of the body results from a lesion probably in the a. Right hemicord b. Right pons c. Right thalamus d. Right temporal lobe

Answer 54

C

Question 55

Numbness on the left side of the face and on the right side of the body results from a lesion probably in the a. Left thalamus b. Left pons c. Right thalamus d. Right pons

Answer 55

B

Question 56

The rate of oligodendroglia to the axons of neurons is usually a. 1:1 b. 1:2 c. 1:50 d. 1:100

Answer 56

C

Question 57

The connective tissue enveloping a nerve fiber is its a. Epineurium b. Perineurium c. Endoneurium d. Myelin sheath

Answer 57

C

Question 58

The myelination of peripheral nerve axons by Schwann cells is by a ratio of: a. 1:1 b. 1:2 c. 1:50 d. 1:100

Answer 58

A

Question 59

The meningeal tissue that forms the periosteum of the inner calvarium is the: a. Dura mater b. Pia mater c. Arachnoid mater d. Alma mater

Answer 59

A

Question 60

The meningeal tissue that is closely adherent to the brain parenchyma is the: a. Dura mater b. Pia mater c. Arachnoid mater d. Alma mater

Answer 60

B

Question 61

The glial cells which form the cuboidal epithelium of the lateral ventricles are the: a. Astrocytes b. Oligodendrocytes c. Microglia d. Ependymal cells

Answer 61

D

Question 62

The caudal end of the spinal cord in adult humans is usually at vertebral body level: a. S4 b. L4 c. T2 d. L2

Answer 62

D

Question 63

A lesion originating from within the core of the spinal cord would usually initially affect the: a. Cervical fibers of the posterior columns b. Cervical fibers of the spinothalamic tract c. Sacral fibers of the posterior columns d. Sacral fibers of the spinothalamic tract

Answer 63

B

Question 64

Due to increased efferent outputs to the extremities the spinal cord has enlargements at which 2 levels? a. Cervical and thoracic levels b. Thoracic and lumbar levels c. Cervical and lumbar levels d. Lumbar and thoracic levels

Answer 64

C

Question 65

The largest neurons in the brain, the pyramidal cells of Betz, are found in which layer of the cerebral cortex? a. Layer 3 b. Layer 4 c. Layer 5 d. Layer 6

Answer 65

C

Question 66

``` This layer is prominent (Line of Gennari) in the visual cortex a. Layer 3 b. Layer 4 c. Layer 5 d. Layer 6 ```

Answer 66

B

Question 67

Pain upon stretching of the meninges by bending the neck is due to innervations of the posterior fossa by a. Cranial nerve V b. Cranial nerve IX and X c. Upper cervical nerves d. Both B & C

Answer 67

D

Question 68

Which of the following is a sensory structure that detects the presence of certain molecules? a. Filiform papilla b. Olfactory epithelium c. Photoreceptor layer d. Organ of Corti

Answer 68

B

Question 69

Olfactory receptors rely on which of the following membrane structures to produce cAMP? a. Cilia b. Microvilli c. cGMP d. G protein

Answer 69

D

Question 70

Which structure relates detected smells to emotions and memories? a. Limbic lobe b. Frontal lobe c. Thalamus d. Temporal lobe

Answer 70

A

Question 71

Umami corresponds to receptors for which of the following? a. Sugars b. Ketones c. Glutamate d. Amino acids

Answer 71

C

Question 72

Homonymous hemianopia is a result of a lesion to which structure? a. Optic nerve b. Optic chiasm c. Optic tract d. Optic radiation

Answer 72

C

Question 73

M cells are connected with this portion of the visual image: a. Motion b. Color c. Form d. Depth

Answer 73

A

Question 74

The effrerent arm of the papillary reflex is found in this structure: a. CN II b. CN III c. edinger-westphal nucleus d. pretectal nucleus

Answer 74

B

Question 75

Which of the following cortical centers is associated with spatial location of images? a. v1 b. v2 c. v3 d. v4

Answer 75

D

Question 76

During the swinging flashlight test, the light was first shone in the right eye and swung to the left eye. Observation: constriction of the pupils with the light on the right eye, then the dilation after the flashlight was swung. Which has the Marcus-Gunn pupil? a. L eye b. R eye c. both eyes d. neither of the two eyes

Answer 76

A

Question 77

Adaptation to the jackhammers on the street and loud club music involves which structure? a. lateral lemniscus b. inferior colliculus c. primary auditory cortex d. superior olivary complex

Answer 77

D

Question 78

Which of the following structures is not connected to the inferior colliculus? a. superior colliculus b. pretectal nucleus c. trapezoid body d. primjary auditory center

Answer 78

C

Question 79

The organ of corti detects which characteristic of sounds? a. volume b. frequency c. timbre d. amplitude

Answer 79

B

Question 80

The actual detection of the vibration within the organ of Corti id due to which structure? a. otoliths b. cohlear nerve c. hair cells d. endolymph

Answer 80

C

Question 81

If your patient talks with a “word salad” where is the probable lesion? a. arcuate fasciculus b. primary auditory cortx c. Wernicke’s area d. Broca’s area

Answer 81

C

Question 82

Which if the following functions is not directly associated with the vestibular sense? a. head position b. eye movement c. spatial hearing d. postural adjustments

Answer 82

C

Question 83

If you spin around while seated on a swivel chair, you are moving the endolymph in which structure? a. superior semicircular canal b. lateral semicircular canal c. anterior semicircular canal d. posterior semicircular canal

Answer 83

B

Question 84

What is the reference structure for the movement of the hair cells’ stereocilia in all vestibular end organs? a. kinocilia b. endolymph c. striola d. otoliths

Answer 84

A

Question 85

When the baseline firing rate of the hair cells within the right lateral SCC increases compared to the left lateral SCC, what phenomenon occurs? a. fast eye movements to the R b. slow eye movements to the R c. Neck muscle contraction on the L d. Head tilt to the R

Answer 85

A

Question 86

If you do a headstand, which of the following structures is most activated? a. superior SCC b. posterior SCC c. Utricle d. Saccule

Answer 86

D

Question 87

The proper sequence of doing a neurological exam a. mental status exam, cranial nerves, motor, meningeal, sensory testing b. cranial nerves, metal starus, motor, meningeal, sensory testing c. mental status, cranial nerves, sensory, motor, meningeal testing d. mental status exam, cranial nerves, motor, sensory, meningeal testing

Answer 87

D

Question 88

If you can only do one test, what would you perform for your patient consulting for acute severe headache a. request for a CT scan of the head b. examine fundus and look for papilledema c. history taking d. do a complete neurological exam

Answer 88

C

Question 89

Patient with the left homonymous hemianopia a. does not have a primary brainstem lesion b. has a lesion in the right parietal lobe c. has a lesion in the right occipital area d. has a lesion in the left optic nerve

Answer 89

C

Question 90

Related to examining the 3rd cranial nerve: a. perform tests for visual acuity, visual confrontation and do opthalmoscopy b. hold the ophthalmoscope in your right hand and move your right eye as you examine the patient’s right eye c. both of the above d. none of the above

Answer 90

D

Question 91

If eye A has a damaged CN 3 and light is given on eye A a. no response in A (negative direct), but positive consensual response of B b. + response in A (positive direct) but – consensual response of B c. – response in A (positive direct) but positive consensual response of B d. none of the above

Answer 91

A

Question 92

A patient with a lesion involving the left cranial nerve V can manifest as: a. can have atrophy of the left temporalis and unable to swallow b. jaw will deviate to the right side because of the weakness of the left lateral pterygoid muscle c. A and B d. none of the above

Answer 92

D

Question 93

In the setting of a left sensorineural hearing loss: a. the webber test will lateralize to the normal ear b. gross hearing will be poor in the left ear c. bone conduction will be greater than air conduction in the left ear d. All of the above e. A and B

Answer 93

E

Question 94

Example of a cortical sensory function test: a. 2 point discrimination b. test of graphesthesia c. Test for stereognosis d. all of the above

Answer 94

D

Question 95

True regarding checking for sensory testing of trunk and limbs: a. dermatome level T10 is at the level of the umbilicus b. when doing the position sense of the hand examine the thumb for accuracy c. during the exam, eyes may be open or close d. Romberg test is a cerebellar exam

Answer 95

A

Question 96

The connective tissue sheath that surrounds the nerve fascicle a. epineurium b. perineurium c. endoneurium d. myelin e. none of the above

Answer 96

B

Question 97

The following are characteristics of the C fibers except: a. small myelinated b. conduction velocity ranges from .5 to 2 m/sec c. conducts dull burning poorly localized pain d. conducts temperature e. no exception

Answer 97

A

Question 98

The following is true of the myelin sheath: a. it is deposited around the axon by Schwann cells b. it is an excellent insulator for the nerve c. it facilitates salutatory conduction d. it increases the velocity of the nerve transmission e. all of the above

Answer 98

E

Question 99

Vibration and position sense is conducted by ______ nerve fibers a. a-alpha b. a-beta c. a-gamma d. a-delta e. a and b

Answer 99

E

Question 100

The following is true of the anterograde axoplasmic transport: a. damaged organelles and recycled plasma membrane are taken in via endocytosis b. axoplasm moves from the axon terminal toward the cell body c. cytoskeletal proteins and organelles are transported away from the cell body d. rabies and herpes viruses enter the axon through this transport system e. heavy metals enter the axon through this system

Answer 100

C

Question 101

The following are characteristics of the skeletal muscle except a. it is made up of numerous muscle fibers ranging from 10-80um in diameter b. it has a true cell membrane called sarcolemma c. bundles of the myofibrils are called muscle fascicles d. sarcoplasmic reticulum is a specialized membrane that is continous with the sarcolemma e. the myofibrils are suspended in the sarcoplasm

Answer 101

C

Question 102

The portion of the myofibril that lies between two successive Z discs is called a. sarcolemma b. sarcoplasm c. sarcomere d. sarcoplasmic reticulum e. sarcoid

Answer 102

C

Question 103

The following lines/ zones disappear during maximum skeletal contraction a. A band and M line b. A band and H zone c. I band and M line d. i band and H zone e. i band and z disc

Answer 103

D

Question 104

The thin myofilament is composed of the following structures except a. titin b. troponin c. tropomyosin d. fibrillar active e. globular actin

Answer 104

A

Question 105

In the sliding filament theory, which of the following statements is correct? a. prior to contraction, the myosin head hydrolyze GTP into the GDP + Pi b. the myosin head binds to tropomyosin to form cross bridges c. the myosin cross bridges will rotate from the center of the sarcolemma d. the binding of an ATP molecule causes detachment of the myosin head e. all are correct

Answer 105

D