Anatomy Flashcards
(233 cards)
1
Q
At what level of the brain is the cerebral aqueduct? Pons?
A
Mesencephalon; Metencephalon
Need to know this for all structures
2
Q
What is the key component to a reflex arc?
A
Interneuron:
- excitatory or inhibitory
- Intrasegmental
- Intersegmental
- Commissural (crosses)
3
Q
What is an example of a monosynaptic reflex? These reflexes do NOT have an interneuron
A
Myotatic reflex, such as knee-jerk or jaw-jerk reflexes
4
Q
What is the sequence of a myotatic reflex? (6)
A
Stimulus (rapid stretching of m.)--> Receptor (neuromuscular spindle)--> Afferent (Ia neuron)--> Efferent (a-motor)--> Effector (extrafusal m.)--> Response (contraction of m.)
Ex: Patellar reflex
5
Q
What is the gamma efferent pathway involving supraspinal influences?
A
Ia afferent neuron--> interneuron--> Alpha motor neuron--> Infrafusal fiber of NMS--> Motor end plate
keeps NMS tight!
6
Q
TQ:
Increased gamma activity leads to….
Decreased gamma activity leads to….
A
- Increased gamma activity=hypertonia and hyperreflexia
- Decreased gamma activity=hypotonia and hyporeflexia
7
Q
The primary neuron is a ______________ neuron whose cell body is located in a ________ganglion. Central process enter CNS and bifurcates to ascend and descend a variable number of segments. Along its course it sends off collaterals to __________ for reflexes. The primary sensory fiber eventually terminates on a ___________ neuron.
A
- pseudounipolar neuron
- spinal ganglion
- interneurons
- secondary neuron
8
Q
The secondary neuron is located in the ___________ (pain and temperature pathway) or in the ________ (proprioceptive pathway)
A
- Spinal cord
- Medulla
9
Q
In a conscious sensory pathway, the secondary axon always decussates and ascends as a __________. It terminates upon a _______ neuron in the dorsal thalamus.
A
- Lemniscus
- Tertiary
10
Q
T/F: A lemniscus is comprised of secondary neurons containing information from the same side.
A
FALSE: A lemniscus contains information from the opposite side!
11
Q
The tertiary neuron is located in a nucleus of the dorsal thalamus. It projects to the ______ ________ ______ via the ________ ______.
A
- Primary somesthetic cortex
- Internal capsule
12
Q
Motor neurons are the last link in a complex motor system that is built on basic reflex circuits. Therefore, lower motor neurons (LMN) are referred to as the “_______ ________ _______”
A
Final common pathway
13
Q
T/F: Without LMN we have no way to respond to our physical environment.
A
True! LMN are the final effectors of the motor system. They are the ones directly connected to the muscle
14
Q
What are the two types of LMN?
What does each innervate?
A
- Alpha motor neurons (innervate extrafusal/skeletal m.)
- Gamma motor neurons (innervate intrafusal/modified mm. of proprioceptive NMS)
15
Q
T/F: Most descending fibers terminate in LMN pools
A
True! There is a somatotopic organization of the anterior horn
16
Q
LMN have alpha and gamma motor neurons that innervate mm. of either __________ or _________ origin.
A
- Branchiomeric (SVE)
- Myotomic (GSE)
17
Q
LMN innervate SVE mm., such as …..(2 examples)
A
- Trigeminal motor nucleus (mastication mm.)
- Facial motor nucleus (mm. of facial expression)
18
Q
LMN innervate GSE mm., such as….(2 examples)
A
- Oculomotor nucleus (LPS, rectus mm., IO)
- Hypoglossal nucleus (intrinsic mm. of the tongue)
19
Q
Pt presents with…Dx?
- Flaccid paralysis (limp)
- Areflexia (no reflex)
- Atonia (gamma motor n. tone gone)
- Atrophy (loss of stim.–>atrophy)
- Fasciculations (twitching or denervated m.)
A
LMN paralysis
Ex: pt with ALS - Hypoglossal n. gone… dysarthria due to paralyzed tongue
20
Q
TQ: Pt presents with….Dx?
- Acute onset lasts b/t 2-4 days with fever, headache, vomiting, neck stiffness, and pain in the back limbs.
- Severe inflammation
- Vasodilation
- Edema
- Macrophage activity
- Neuronal death
- Astrocyte gliosis
A
Acute anterior poliomyelitis
-Selectively involves the LMNs of the anterior horns and CN motor nuclei
21
Q
The pyramidal system of the conscious sensory pathway is the ___________ pathway.
A
Corticospinal
22
Q
The __________ tract descends through the corona radiata, internal capsule, cerebral peduncles, pons, and upper medulla. 85%-90% of the fibers decussate at the pyramidal decussation and forms the _______ _____________ _____. Most of the fibers terminate in LMN pools.
A
- Corticospinal tract (CST)
- Lateral corticospinal tract (LCST)
23
Q
Unilateral lesions of the LCST result in (ipsilateral/contralateral) paralysis or paresis of the (proximal/distal) limb musculature innervated by those spinal segments below the level of the lesion.
A
- Ipsilateral
- Distal
24
Q
For the corticospinal fibers that do NOT cross at the decussation, they continue as the ________________. Unilateral lesions have clinical effect.
A
Anterior corticospinal tract (ACST)
minimal clinical effect
25
The inability to play the piano may mean that you have issues with which tract? Why?
The lateral corticospinal tract (LCST)
This tract involves the precise individualized movements of the digits. A unilateral lesion of this group results in significant motor dysfunction of the distal extremities leading to clumsiness and weakness.
26
The anterior corticospinal tract and reticulospinal tract exert (unilateral/bilateral) influences upon ___ pools.
- Bilateral
| - LMN
27
UMN paralysis is commonly due to interruption of what? (3)
Motor cortex
Corticospinal tracts
Corticobulbar tracts
28
Pt presents with S/S:
- Spastic paresis of the axial and proximal limb, upper extremity spastic paralysis of distal limb
- Hypertonia and hyperreflexia
- Babinski sign (fanning of toes)
- Clonus
- Rigidity
- Disuse atrophy
(Pt. flexed in upper extremity, extended and supinated in lower extremity with pigeon toed feet)
UMN paralysis
| referred to as a spastic paralysis of the antigravity mm.
29
What are the 3 phases of physical events following UMN lesions?
1) Spinal shock with areflexia, atonia, flaccid paralysis
2) Wks-mo return of basic spinal reflexes (recovered from shock), but still spastic paresis and paralysis
3) 1-2 yrs, muscle spasms of the extensors, flexors, or flaccidity
30
Abnormal, passive resistance to movement in one direction is called?
Spasticity
31
Pt presents with...Dx?
- Paralyzed movements in hemiplegic, quadriplegic, or paraplegic distribution (not individual muscle)
- Atrophy of disuse (late/slight)
- Hyperactive DTR
- Clonus
- Clasp-Knife spasticity
- Absent abdominal/cremasteric reflexes
- Babinski sign
UMN lesion!
32
Pt presents with....Dx?
- Paralyzed individual mm. or sets of mm. in root or peripheral n. distrib.
- Atrophy of denervation (early/severe)
- Fasciculations
- Hypoactive or absent DTR
- Hypotonia
LMN lesion!
33
Pt presents with...Dx?
- LMN paresis and atrophy of intrinsic mm. of hands, followed later by the arms and shoulder mm.
- Dysarthria, dysphagia, and paresis of the tongue (LMN)
- Spastic paralysis, hyperflexia, and babinski sign due to corticospinal tract involvement (UMN)
- NO sensory deficits!
ALS (amyotrophic lateral sclerosis)
- cause unknown (glutamate metab?)
- Avg. onset=66 yo
LMN: Anterior Horn Cells, Hypoglossal Nucleus, Nucleus Ambiguus, Facial Motor Nucleus
UMN: Chronic, progressive degeneration of the Corticospinal Tracts
34
Name the region the fx belongs to:
| -Ascending tracts for proprioception, 2 pt tactile discrimination, vibratory sensations
Posterior region:
| Posterior columns
35
The distinct ascending tracts provide a "direct line" system to the _______ and _______.
What is this system called?
(Direct/Indirect) spinothalamic pathway
- Thalamus
- Cortex
Direct spinothalamic pathway
36
The direct spinothalamic pathways is a "labeled line" in that detailed sensory information from a specific part of the body has its own "direct-line wiring" to the thalamus and cortex. This is also called __________ ___________.
Somatotropic organization
37
Sharp-pricking, highly-localized pain is conveyed via the ______ _____________ pathway. This is part of the ______________ system.
Which type of primary neurons are involved?
- Direct spinothalamic (fast pain)
- Neospinothalamic
- A-delta fibers (myelinated, fast)
38
Burning, deep, dull, aching, diffuse pain are conveyed via the ________ ____________ pathway. This is part of the _______________ system.
What type of primary fibers are involved?
- Indirect spinothalmic pathway (slow pain)
- Paleospinothalamic tract
- C fibers (unmyelinated, slow)
39
The primary fibers of the indirect spinothalamic pathway enter the spinal cord, bifurcate, and ascend and descend to a variable # of segment sin the dorsolateral fasciculus of Lissaur. Throughout its course it sends thousands of collateral terminals to the nucleus proprius. From the NP, the fibers may ascend as spinoreticular fibers within the fasciuclus proprius to the thalamus. The fasciculus proprius is part of the _________ _________, which surrounds the gray matter of the spinal cord.
Reticular formation
40
Unilateral lesions of the spinoreticular fibers do not result in significant sensory deficits because its too bilateral and diffuse to be affected. Bilateral lesions (spinal cord transections) may eliminate crude pain but if it is incomplete or at different levels then cannot eliminate the pain. What is this the basis of?
Neuroanatomical basis of persistent or intractable pain
41
The ______ ___________ pathway (fast pain) primary axon (A delta or C) enters the spinal cord, bifurcates, and ascends and descends 2 spinal cord segments (2 sensory dermatomes) in the dorsolateral fasciculus (Fasciculus of Lissaur). The secondary neuron is in the Substantia Gelatinosa (A delta) or nucleus proprius (C). The secondary fibers from the SG (A delta) sends axons through the anterior white commissure to ascend in the anterolateral funiculus as the lateral spinothalamic tract (LSTT). In the medulla, the LSTT joins the VSTT to form the spinal lemniscus. The secondary neurons of the spinal lemniscus terminate in the VPL nucleus of the dorsal thalamus, where the tertiary neurons project to the primary somesthetic cortex.
Note: only 1/3 of LSTT fibers reach the thalamus.
-Direct spinothalamic
42
The VPL nucleus receives sensory information from the contralateral 1/2 of the body via the ______ __________.
Spinal lemniscus
43
Contralateral loss of pain and temperature sensation two sensory dermatomal segments below the level of the lesion.
Where is the lesion?
(Unilateral/Bilateral) lesion of the ____
Unilateral lesion of the LSTT
44
Contralateral hemianalgesia and thermal hemianesthesia..
Where is the lesion?
(Unilateral/Bilateral) lesion of the ______ _________
Unilateral lesion of the spinal lemniscus
45
Grabbing a door handle is dependent on what type of crude tactile discrimination? (comprises roughness, texture, form, localization)
Passive touch = Ventral spinothalamic pathway
"I am in contact with something"
46
TQ: What type of touch is conveyed by the posterior column/medial lemniscal system (direct line for sensory)? It is associated with learning tactile discrimination, 2 pt tactile discrim, stereognosis (awareness of shape size and texture), proprioception, vibrations, and weight.
Active touch
"I am feeling a penny"
47
The _______ _____________ pathway conveys light passive touch, crude tactile sensations, and pressure. The central processes of primary neurons course through the medial division of the dorsal root, enters the posterior funiculus, bifurcates, and ascends 6-10 segments, while sending collateral terminals to secondary neurons in the ipsilateral NP and intermediate gray. The secondary neurons from the nucleus proprius cross the anterior white commissure and form an ascending tract (VSTT). In the medulla, the VSTT joins the LSTT to form the spinal lemniscus. The spinal lemniscus terminates on tertiary neurons in the VPL nucleus of the dorsal thalamus. Tertiary neurons project to the primary somesthetic cortex via the posterior limb of the internal capsule.
Ventral spinothalamic pathway (VST)
48
Clinically, unilateral lesions of the VSTT may be difficult to lose crude touch because fibers ascend in both the posterior (primary fibers) and anterolateral funiculi (secondary fibers). Also deficits of both the VSTT and spinal lemniscus may be masked by the intact _______________________.
Posterior column/medial lemniscal system
49
Primary neurons of the _____________________ system are the fastest and longest neurons in the sensory system. Some of these neurons extend from the tip of the toe to the medulla. (6 ft long in a basketball player at over 200 mph)
Posterior column/medial lemniscal system
50
Primary neurons of the PC/ML system enter the posterior column of the spinal cord and segregate into the appropriate fasciculus. If the information is from the lower extremity, the fibers will ascend in the __________ ________. If the information is from the upper extremity, the fibers will ascend in the __________ ________.
- Fasciculus gracilis
| - Fasciculus cuneatus
51
What kind of information does the fasciculus gracilis convey and from where?
(Below dermatome __)
-Proprioception, 2-pt tactile discrimination, and vibratory sensations
-Lower extremities and body
(Below dermatome T6)
52
What kind of information does the fasciculus cuneatus convey and from where?
(Down to dermatome __)
-Proprioception, 2-pt tactile discrimination, and vibratory sensations
-Upper extremities and body;
(Down to dermatome T7)
53
T/F: The fasciculus cuneatus is not present in the spinal cord below the level of the 6th thoracic cord segment
True!
54
In the medulla, the secondary axons from the nucleus gracilis and cuneatus decussate as ________ _______ ______ and form the ______ _________, which terminates on the VPL nucleus.
- Internal arcuate fibers
| - Medial lemniscus
55
Which spinocerebellar (unconscious) pathway deals with precise proprioception of individual muscles in the upper extremity? Lower extremity?
- Upper extremity: Cuneocerebellar tract
| - Lower extremity: Dorsal spinocerebellar tract
56
Which spinocerebellar (unconscious) pathway deals with gross proprioception of the whole limb in the upper extremity? Lower extremity?
- Upper extremity: Rostral spinocerebellar tract
| - Lower extremity: Ventral spinocerebellar tract
57
Pt presents with....Dx?
| -loss of proprioception, 2-pt tactile discrimination on the right lower half of body and right lower extremity
right unilateral lesion of the fasciculus gracillis (ipsilateral loss of proprioception, 2 pt tactile discrim to the lower half of body/extremity)
58
Pt presents with....Dx?
| -loss of proprioception, 2-pt tactile discrimination on the left upper half of body and left upper extremity
left unilateral lesion of the fasciculus cuneatus (ipsilateral loss of proprioception, 2 pt tactile discrim. to the upper half of body/extremity)
59
Pt presents with...Dx?
| -loss of proprioception, 2-pt tactile discrimination on the right side of the body and limbs.
left unilateral lesion of the medial lemniscus
| opposite side of body has loss of proprio and 2 pt
60
Pt presents with....Dx?
- hypotonia and/or atonia
- diminished motor reflexes
- atonic bladder and painless urine retention
-Lesion of the dorsal root
| could be tabes dorsalis
61
```
Pt presents with...dx?
spastic paralysis
hyperreflexia
hypertonia
babinski sign
clonus
disuse atrophy
```
LCST (lateral corticospinal tract) lesion
62
Pt presents with:
- urinary retention
- later presents with reflex bladder
- LRST lesion
| - Transection of spinal cord above S2
63
Pt presents with right sided loss of pain and temperature sensation from T8 dermatome to the toe. Dx?
Lesion of the left LSTT at T6 (lateral spinothalamic tract)
| contralateral loss of pain and temperature sensation two sensory dermatomal segments below the level of the lesion
64
Pt presents with bilateral loss of pain and temperature sensations in the upper extremities. Dx?
Anterior white commisure lesion leads to yoke-like anestheisa (shoulder region)
65
```
Pt presents with....dx?
flaccid paralysis
areflexia
atonia
atrophy
fasciculations
```
LMN paralysis via lesion of the anterior horn cells
66
Fibers in the medial division of the dorsal root enter the post. column and convey_______________; fibers in the lateral division of the dorsal root enter the dorsolateral fasciculus of lissaur and convey _____________.
proprioception, 2 pt tactile, and vibratory info
pain and temperature info
67
What dz allows the nonnociceptive fibers to "close" the gate, leading to insensitivity to pain.
congenital absence of C type fibers
| disinhib of SG, decrease in C fibers close gate
68
What infection may compromise the non-nociceptive A α/β fibers, thereby allowing nociceptive C fibers to "open" the gate. The person has increased sensitivity to pain from the sensory dermatome of the affected nerve ex: mandibular.
Herpes zoster infection (shingles)
| inhib of SG, A fibers opens gate
69
While undergoing an anterolateral cordotomy to treat intractable pain of LSTT, the surgeons will cut the cord ________above and on the ________side of the area of pain.
two segments above and on the opposite side
70
Pt presents with left sided analgesia and left sided thermal anesthesia?
Right unilateral lesion of the spinal lemniscus
71
T/F: You can have a peripeheral n. lesion of the spinal lemniscus
FALSE: CANNOT get peripheral n. lesion with the spinal lemniscus. Pain and temperature only!
72
______plays a significant role in the emotional importance and response we have to pain
prefrontal lobes
73
Pt presents with....dx?
CC: progressive bilateral weakness of her upper extremities of 3-4 years
1) bilateral loss of pain and temperature sensations in the upper extremities***
2) spastic paralysis, hyperreflexia, hypertonia of the lower extremity
3) flaccid paralysis, atrophy, areflexia, atonia of the upper extremity
4) loss of proprioception and 2 pt tactile sensations
Syringomyelia: gross cavitation of the central canal affecting the cervical region of the spinal cord. As the lesion extends laterally into the LSTT, deep pain impaired first!
Destruction of:
1) anterior white commisure (LMN)
2) lateral corticospinal tracts (UMN)
3) anterior horn (LMN)
4) posterior columns
74
__________axons are all primary axons and therefore result in ipsilateral deficits. Lesions of secondary axons are contralateral deficits.
Posterior column
75
Pt presents with...Dx?
- Lightning pains from lower limbs for several years
- Atonic bladder (urine retention)
- Broad base gait with slapping of the feet
- (+) Romberg test
- Argyll Robertson pupil: pupils unreactive to light, but constrict during accommodation
Tabes dorsalis! a meningiovascular inflammation of the blood vessels as they pierce through the pia at the junction of the dorsal roots and posterior columns. Occurs in tertiary syphilis.
76
T/F: The spinal cord level is always the same as the vertebral body level.
FALSE: The more superior you are the more they are equal.
Ex: T9 vertebral body=T10 spinal cord
77
At what vertebral level does the spinal cord end?
L1-L2 interspace
Conus medullaris level changes with age.
78
What a. supplies the central area of the spinal cord?
anterior spinal a. (off vertebral)
79
What a. supplies the posterior portion of the spinal cord?
Posterior spinal a.
80
Pt presents with big pulsatile mass on the spinal cord leading to neuronal dysfunction, including spastic paraplegia and hyperactive neurons.
Arteriovenous malformation (AVM): no capillary bed between the a. and v.
81
What may be compromised secondary to repair of AAA leading to paraplegia?
The great anterior a. of Adamkeiwicz
82
Spinal cord trauma may interrupt the blood supply to the spinal cord, especially in those vulnerable regions served by two arterial supplies, such as....
areas at C2-3, T1-4, L1
83
The result of ischemic necrosis of the spinal cord is...
partial or complete transection of the spinal cord
84
The gamma efferent pathways controls...
muscle tone and proprioception
85
Alpha and gamma motor neurons are ____________, which means they directly innervate a muscle
lower motor neurons
86
The net result of the gamma efferent pathway is an alteration in ___________and reflexes, and the maintenance of accurate proprioceptive (position-sense) output from the ___________.
muscle tone
| neuromuscular spindles
87
Both hypertonia and hypotonia result in a decrease in the degree and accuracy of movement performed by an affected muscle, and a change in reflex activity. Proprioceptive cues and resultant reflexes are distorted. Which pathway is involved?
The gamma efferent pathway
88
The gamma efferent pathway keeps the NMS toned during contraction , which is necessary for....
accurate proprioceptive information! Need accurate proprio. to have accurate motor activity.
89
```
Name the location and function of the sensory nucleus:
substantia gelatinosa (SG)
```
Posterolateral tip of the dorsal horn at all spinal levels
Pain/temperature pathway
90
```
Name the location and function of the sensory nucleus:
nucleus proprius (NP)
```
Mid-portion of the dorsal horn
Pain/temperature pathway
91
```
Name the location and function of the sensory nucleus:
nucleus dorsalis (clarke's column)
```
C8-L2
Unconscious proprio.
92
```
Name the location and function of the sensory nucleus:
visceral afferent (VA) nucleus
```
T1-L2, S2-4
Visceral sensory integration
93
```
Name the location and function of the sensory nucleus:
intermediate gray (IG)
```
All spinal levels
Sensorimotor integration center
94
Name the location and function of the motor nucleus:
| Medial motor cell column (MMCC)
Medial part of the ventral horn at all levels
Axial muscles
95
Name the location and function of the motor nucleus:
| Lateral motor cell column (LMCC)
later part of the ventral horn in the cervical and lumbosacral enlargements
Limb/extremity muscles
96
Name the location and function of the motor nucleus:
| Phrenic nucleus
subdivision of the MMCC
Respiratory diaphragm
97
Name the location and function of the motor nucleus:
| Sacral autonomic nucleus (SAN)
Lateral horn S2-4
Preganglionic parasympathetic fibers
98
The dorsolateral fasciculus of Lissaur comprises mainly primary sensory fibers that are poorly myelinated and represent the primary axons in the _________________pathway ("fast" pain pathway).
direct spinothalamic
99
_______________fibers of the posterior column primary neurons ascend and terminate on secondary neurons in the dorsal horn and intermediate gray. The axons of the secondary neurons in this pathway form the contralateral __________for conveying passive touch.
short ascending fibers
ventral spinothalamic tract (VSTT)
100
________________fibers of the posterior column primary neurons extend from the level of entrance into the spinal cord up to the medulla. These fibers form the FG and FC.
long ascending fibers
101
which two tracts are embedded in the fasciculus proprius?
spinoreticular tract (slow visceral pain)
reticulospinal tract (MRST & LRST)
102
Which ascending tact coneys pain and temperature information and originates from the substantia gelatinosa and nucleus proprius? What does a unilateral lesion result in?
Lateral spinothalamic tract
A unilateral lesion of the LSTT in the spinal cord results in a contralateral loss of pain and temperature two sensory dermatomal segments below the lesion.
A unilateral lesion of the spinal lemniscus results in a contralateral hemianalgesia [loss of pain sensations] and thermal hemianesthesia [loss of temperature sensations
103
Which two tracts of the lateral descending group are involved in the control of distal limb musculature, especially precise, individualized movements of the digits, like typing on the keyboard. Where do each terminate?
Lateral corticospinal tract (LCST): terminates in ant. horn and intermediate gray of all spinal levels
Rubrospinal tract (RST): terminates in the intermediate gray at all levels.
104
Which descending group exert bilateral control of axial and proximal limb mm. during postural movements? (lesions have min. effect)
Anteromedial descending group
105
Where is the lesion?
Ipsilateral loss of proprioceptive and 2-point tactile sensations from all or part of the sensory dermatomal segments which are below the lesion and above T7
Unilateral lesion of the fasciculus cuneatus in the spinal cord (from C1 to T6)
106
Where is the lesion?
| Contralateral of proprioception and 2-point tactile hemianesthesia.
Unilateral lesion of the medial lemniscus in the medulla
107
Where is the lesion?
| Contralateral loss of pain and temperature two sensory dermatomal segments below the lesion
Unilateral lesion of the LSTT in the spinal cord
108
Where is the lesion?
| Contralateral hemianalgesia [loss of pain sensations] and thermal hemianesthesia [loss of temperature sensations]
Unilateral lesion of the spinal lemniscus
109
Pt presents with...Dx?
- Loss of all sensations, reflex activities
- Bilateral flaccid paralysis of involved extremities
- Loss of voluntary control of a spastic urinary bladder
- Loss in sexual potency in the male
- Various visceral deficits (loss of thermoregulation (cool, dry, skin with no sweating)
- Transient Horner's syndrome, if the lesion is above T2
Spinal shock due to transected spinal cord
110
Pt. presents with respiratory depression. What spinal cord level is the lesion?
C1-4 (phrenic nucleus)
111
Pt. presents with horner's syndrome. What spinal cord level is the lesion?
Above T1 (lesion of reticulospinal fibers)
112
Pt. presents with reflex bladder. What spinal cord level is the lesion?
S2 (distention of bladder wall results in reflex/incomplete voiding)
113
Pt. presents with bowl incontinence. What spinal cord level is the lesion?
S3-5
114
Are reflexes hyper or absent in LMN lesion?
absent! (no output to m.)
115
Are reflexes hyper or absent in UMN lesion?
hyperactive (no desc. influence to tone it done)
116
Pt presents with the following after bullet wound...Dx?
1) Loss of pain and temperature on right lower extremity (L3-S4)
2) Loss of left lower limb proprioception and 2 pt. tactile
3) Spastic paralysis of the left lower limb
4) Hyperreflexia and hypertonia of the left lower limb
5) Babinski sign and ankle clonus on the left
Brown-Sequard Syndrome
1) LSTT
2) Posterior columns
3) Descending motor tracts
4,5) LCST (UMN)
117
Pt presents with....Dx?
- Numbness and tingling in the fingers and toes (glove and stocking anesthesia)
- Bilateral loss of proprioception and vibratory sensations
- UMN signs such as spastic paralysis, paresis, hyperreflexia, and Babinski
- Fair hair, pink cheeks, sore tongue
Subacute combined degeneration and pernicious anemia
Degeneration of the posterior columns and LCST due to vit. B12 def
118
Name the clinically important structures of the spinal cord (7)
1. Dorsal roots: diminished tone and reflexes
2. Posterior columns: ipsil loss of proprio, 2 pt tactile below the lesion level
3. LCST: ipsil UMN spastic paralysis
4. LSTT: contra loss of pain and temp 2 sensory derm below lesion
5. LRST: hornes syndrome (Above T1); bladder bowl incont.
6. Anterior Horn: LMN paralysis paresis
7. Anterior white commissure: yolk like anesthesia pain and temp. ; LMN
119
The primary axons (of the pseudounipolar neurons) enter the brainstem at the middle cerebellar peduncle, and bifurcate into short ascending and long descending roots. These fibers convey general tactile information to both the ____ ______ nucleus, and the _______ _______ and _________ of the descending nucleus of V.
main sensory nucleus
subnuclei rostralis and interpolaris of the descending nucleus of V
120
A few incoming primary axons of the trigeminal ganglion will ascend only in the short ascending root (tract) of V and terminate in the ____ _____ ____ __ __. These fibers convey what type of information from the the face?
main sensory nucleus of V
precise discriminative tactile information from the face
121
Some fibers adjacent to the ascending root course in the mesencephalic tract of V. This tract conveys ____________ information to the ____ _______ nucleus.
proprioceptive information
main sensory nucleus
122
Half of the incoming primary fibers will descend only in the descending root (tract) of V, and terminate in the _______ _____ of the ____________ ______ __ __. These fibers convey _____ and ______ from the face.
subnucleus caudalis of the descending nucleus of V.
convey pain and temperature
123
Within the brainstem, the central processes of all GSA components course the in the ________ _____ __ __.
descending root of V
124
Name the function of these trigeminal nerve fibers:
Ascending fibers:
Mesencephalic nucleus of V:
Descending fibers:
Ascending fibers: precise discriminative from face
Mesencephalic nucleus of V: proprioceptive fibers
Descending fibers: pain & temp
125
The main sensory nucleus of the trigeminal n. is analogous to the nuclei ______ and ______. It is located at the level of the trigeminal nerve (pierces the middle cerebellar peduncle)
nuclei gracilis and cuneatus
126
The main sensory nucleus receives _____ tactile, ____ tactile and ____________ information from the face.
precise tactile, crude tactile, and proprioceptive information
127
The descending (spinal) nucleus of V is continuous with and analogous to the ________ _________ __ ______ in the spinal cord.
dorsolateral fasciculus of Lissauer
128
All pain and temperature sensations as well as general tactile info from the face terminate in one or more of the descending nucleus of V's 3 nuclei:
__________ ________
__________ ___________
__________ ________
Subnucleus rostralis
Subnucleus interpolaris
Subnucleus caudalis
129
The subnucleus rostralis extends from the level of the entrance of V to the upper medulla (pontomedullary sulcus). It receives tactile info from the _____ region of the face.
central region
130
The subnucleus interpolaris extends from the upper medulla to the level of the obex. It receives info from the __________ region of the face.
peripheral regoin
131
The subnucleus caudalis extends from the level of the obex to the second cervical level. It is continuous with the _______ _________and receives_____ and __________ info from the anterior 1/2 of the head.
substantia gelatinosa
pain and temperature
132
TQ: The only nucleus in the CNS comprised of pseudounipolar neurons....
Mesencephalic nucleus of V
133
The trigeminal motor nucleus is at the same level of the brainstem as the _____ ________ nucleus.
main sensory nucleus
134
The pain pathways from the face is as follows:
- Primary axons from the trigeminal N descend in the descending root of V, terminate in the subnucleus caudalis.
- Secondary axons decussate and ascend in the ________ ________, which terminates in the VPM (ventral posterior medial) nucleus of the dorsal thalamus.
- Tertiary axons from the VPM project via the posterior limb of the internal capsule to the head region of the primary somesthetic cortex
- Trigeminoreticular fibers from the subnucleus caudalis project bilaterally to the brainstem reticular formation, which facilitates the ______ ______ _______ ______ (ARAS).
trigeminal lemniscus (TL)
Ascending reticular activating system (ARAS)
135
ARAS plays an important role in ______ and ______.
arousal and alertness
136
The crude tactile pathway from the face is as follows:
- After entering the brainstem, many primary axons bifurcate into ascend and descend roots. These fibers convey general tactile info to both the main sensory nucleus and the subnuclei rostralis and interpolaris of the descending nucleus of V.
- Secondary axons in the crude tactile pathway decussate and ascend in the _________ ________. Some remain uncrossed and ascend int he ipsilateral _____ _____ ________ _____. Terminate in VPM nucleus.
- Tertiary axons from the VPM nucleus->primary somesthetic cortex
trigeminal lemniscus
dorsal central trigeminal tract (DCTT)
137
Crude tactile information from the face has a degree of _________ to its ascending pathways and therefore is protected from ________ lesion
bilaterally
unilateral
138
The precise tactile pathway from the face is as follows:
- Incoming primary neurons may ascend only in the short ascending root of V and terminate in the ____ _____ nucleus of V. These fibers convey precise tactile info from the face.
- Most secondary axons conveying precise 2-pt tactile info from the main sensory nucleus ascend in the ipsilateral _____ _____ _________ _____, which terminates in the ipsilateral VPM nucleus.
- Some fibers may decussate and ascend in the ______ ________.
main sensory nucleus of V
dorsal central trigeminal tract (DCTT)
trigeminal lemniscus
139
The proprioceptive pathways from the face is as follows:
- The cell body of the primary neuron is in the __________ nucleus, the only nucleus in the CNS composed of ________________ neurons.
- The central process terminates in the _____ ______ nucleus, which permits the conscious awareness of facial and oral proprio via the trigeminal lemniscus and the DCTT
- Some central processes terminate directly upon the _____ ______ ______, which makes the monosynaptic ____-____ reflex.
mesencephalic nucleus; pseudounipolar neurons
main sensory nucleus
trigeminal motor nucleus
jaw-jerk
140
The trigeminocerebellar tract is as follows:
- Only the _______ ______ and ______ project into the cerebellum, which project fibers to the anterior vermis via the ________ cerebellar peduncle. These fibers convey CRUDE tactile info from the head.
- A moderate number of secondary neurons in the ____ _____ ______ project to the anterior vermis of the cerebellum via the _______ cerebellar peduncle. These fibers contain PRECISE tactile and proprio info from the head.
subnuclei rostralis and interpolaris; inferior
main sensory nucleus; superior cerebellar peduncle
141
Pt presents with....DX?
- Anesthesia and loss of general sensations in the trigeminal dermatomes
- Loss of jaw jerk reflex
- Atrophy of the muscles of mastication
- Loss of ipsilateral and consensual corneal reflex
Unilateral lesion of the trigeminal N.
142
Pt presents with...Dx?
- ipsilateral hemianalgesia of the face
- contralateral hemianalgesia of the body
Alternating analgesia from a brainstem lesion in the upper medulla
Destroys the primary fibers in the descending tract of V, and the secondary fibers in the spinal lemniscus.
143
TQ Pt presents with....Dx?
- ipsilateral trigeminal anesthesia and paralysis
- contralateral spastic hemiplegia
Alternating Trigeminal Hemiplegia
Result of a unilateral destruction of the trigeminal nerve and corticospinal tract in the pons
144
Pt presents with....Dx?
-An intractable, lacerating facial pain, which follows the distribution of the affected division of the trigeminal nerve.
Trigeminal neuralgia (Tic Douloureux)
A cutaneous region on the head, called a trigger zone, may initiate abnormal,” epileptic-like" discharges from the subnucleus caudalis.
145
How can we treat trigeminal neuralgia?
- anticonvulsant medication
- cryosurgery of the trigeminal ganglion
- trigeminal or medullary tractotomy.
146
Postlingually deaf individuals may experience ___________ ______while reading lips. These people use their audtiroy memory and associates to translate the visual image of the lips moving to an auditory correlate.
phantasmal voices
147
The auditory system is more ________ than any other system.
bilateral
148
The dorsal stria is visible as the _____ ______ _______. Both the dorsal and intermediate striae decussate in the upper medulla and ascend in the contralateral _______ _______, which terminates upon neurons in the ______ ________.
stria medullaris acoustica
lateral lemniscus (LL)
inferior colliculus
149
The ventral acoustic stria terminate bilaterally in the _________ _______ _____, which projects fibers to the inferior colliculus through the ipsilateral _______ _______.
superior olivary nucleus (SON)
lateral lemniscus
150
Fibers from the inferior colliculus project to the ____ _____ _____ via the _______ of the inferior colliculus.
medial geniculate body
brachium
151
Fibers form the medial geniculate body project to the primary auditory cortex via the _________ radiations
sublenticular (auditory)
152
The primary auditory cortex is located in the ______ _____ gyrus.
superior temporal
153
The superior olivary nuclear complex plays a role in modifying auditory information:
- The medial superior olivary nucleus is important in ________ ______.
- The lateral superior olivary nucleus gives rise to the the _________ ________, which exert inhibitory influences upon the organ of Corti.
localizing sounds
olivocochlear efferents
154
Loud noises overtime can destroy neuroepithelial cells of the ____ __ ______, which leads to hearing loss.
Organ of Corti
155
Name the lesion:
| -ipsilateral complete deafness
Unilateral lesion of the Cochlear nerve
156
Name the lesion:
- Bilateral loss of hearing, which is more prominent in the contralateral ear.
- These structures include the lateral lemniscus, inferior colliculus and brachium, and the medial geniculate body.
Unilateral lesion of the central auditory pathway
157
Name the lesion:
| -difficulty in localizing sounds and tone discrimination. It does not result in hearing deficits
Lesions of the Primary Auditory Cortex
geriatric pts
158
Name the lesion:
- This fluent language disorder is characterized by severe impairment of repetition, difficulty in reading aloud
- A right hemiparesis and hemianopia as well as orofacial and bilateral limb apraxia may be present.
Conduction aphasia: A lesion of the arcuate fasciculus
159
TQ Name the lesion:
- auditory agnosia characterized by an inability to comprehend auditory information.
- Spoken and written language as well as other sensory modalities may remain intact.
Auditory agnosia: lesion in the auditory assoc. cortex
160
Name the lesion:
- patient's unable to comprehend the spoken or written word
- Patient can speak quite fluently
Wernicke's aphasia
161
Clinically, lesions of the visual system are always described in terms of their _____ _____ ______.
Visual field deficits
162
The retinal field is divided into 2 halves. What are they?
nasal and temporal hemiretinas
163
The visual field projects an ______ and _______ image onto the retinal field.
inverted and reversed
164
The temporal visual field projects to the nasal retina, while the nasal visual field projects onto the ______ ______.
temporal retina
165
T/F: Visual deficits are described from the perspective of the patient's right or left.
TRUE
166
The rules of the retinotopic projection include the fact that fibers from the temporal hemiretina do/do not cross in the optic chiasma whereas fibers form the nasal hemiretina do/do not cross in the optic chiasma.
Fibers from the temporal hemiretina do NOT cross in the optic chiasma; whereas fibers from the nasal hemiretina DO cross in the optic chiasma.
167
The rules of retinotopic projection include the rule of L's:
Information from the ______ _________ projects to the Lateral part of the Lateral geniculate body, Loop of meyer, and the Lingual gyrus.
Lower hemiretina
168
Optic N.-->optic chiasma-->optic tract (passes over cerebral peduncles)-->lateral geniculate body->____ ________->primary visual cortex
optic radiations
169
TQ: Since axons from the nasal hemiretina cross in the optic chiasma, _____ _____ which push on the chiasm, may result in field blindness (bitermporal hemianopia)
pituitary tumors
170
The optic tract extends from the optic chiasma to the _______ _______ ____.
Lateral geniculate body
171
Optic radiation's loop of Meyer is located in the _____ aspect of the ______ lobe. Lesions may affect only one part of the optic radiations.
posterior aspect of the temporal lobe
172
T/F: The visual system is cortically dependent (primary visual cortex) and will undergo retrograde-synaptic degeneration without the cortex.
True
173
_________ ____ _____ refer to corresponding halves of visual fields such as the temporal field of one eye and the nasal field of the other.
Homonymous visual fields
174
Stopped at stop sign looking straight ahead. Through peripheral vision, you see a car approaching from the right side. The car is entering your ____ _______ visual field. As it moves closer to the intersection, your left eye also sees the car entering its ____ _____ field from the right. The car is traveling through homonymous visual fields.
right temporal visual field
right nasal visual field
175
__________ ____ _____ refer to non-corresponding visual fields (temporal field of one eye and temporal field of the other)
Heteronymous visual fields
176
Testing visual fields:
Clinically, visual fields may be assessed with the patient looking straight at the examiner, and moving an object from outside the patient's peripheral vision into the perimeter of vision of each eye. Both of the patient's eyes may be open when testing the _______ ____. However, one eye must be closed or shielded from view when testing the _____ _____ field of the other eye.
temporal fields
nasal visual field
177
Blindness of one-half of the visual field...
hemianopia
178
A nasal hemianopia of the left eye indicates a lesion of the _______ ______ of the ____ eye.
temporal hemiretina of the left eye
179
A blindness of a quadrant of the visual field...
Quadrantanopia
180
Quadrantanopia involving the upper nasal quadrant of one eye and the upper temporal quadrant of the other eye...
superior quadrantanopia (a homonymous lesion)
181
Monocular blindness is due to what lesion? What does it look like?
unilateral lesion of the optic n.
| loose nasal and temporal hemiretina in one eye (cant see out of one eye)
182
Bilateral lesion of the lateral aspect of the optic chiasma would be seen as....
binasal hemianopia : heteronymous blindness in the nasal fields of each eye.
May be unilateral because also due to atherosclerosis or aneurysm of ICA
temporal hemiretina cut off so blind in nasal field
183
unilateral lesion of the lateral aspect of the optic chiasma results in....
hemianopia of the ipsilateral eye
Ex: right nasal hemianopia of the left eye (lesion of the temporal retina of the left eye)
184
TQ: Midline lesion of the optic chiasma may be caused by pituitary tumors...leads to
bitemporal hemianopia (heteronymous deficit)
no temporal fields
185
Unilateral lesions of the lateral geniculate body, complete optic radiations, or visual cortex results in __________ _______ _______.
contralateral homonymous hemianopia
186
lose temporal visual field in left eye and nasal visual field in right eye is an example of....
left homonymous hemianopia which would indicate a lesion on the right visual pathway
trouble seeing things from left so pt. CC is blind in left eye
187
unilateral lesions of the loop of Meyer usually result in ___________ ______ ___________
contralateral superior quadrantanopia (homonymous deficit): upper temporal field and upper nasal field gone
Left superior quadrantanopia is a lesion of the right loop of meyer
188
A tumor or infarction of the posterior temporal lobe may lead to a....
contralateral superior quadrantanopia
189
Incongruent contralateral homonymous hemianopia with macular sparing is usually indicative of a ______ lesion of the _____ _____.
unilateral lesion of the visual cortex
190
Incongruent contralateral homonymous hemianopia may be due to an obstruction of the ______ cerebral artery.
posterior
191
Lesions of the visual cortex are usually_________ (asymmetrical) whereas lesions of the LGB or optic radiations are symmetrical.
incongruous
192
Left incongruent homonymous hemianopia with macular sparing is lesion of the ______ primary visual cortex.
right
193
Horner's syndrome involves interruption of the ______ reflex due to the interruption of the ILCC to T1.
light
ipsilateral pupillary constriction, slight ptosis etc
194
Accommodation is a cortically mediated visual response which originates in the frontal eye field of the frontal lobe. The triad of accommodation includes:
- convergence of vision
- pupillary constriction
- thickening of lens
195
Argyll-robinson pupil is accommodating but _________ due to loss of the pretectum
unreactive
196
Holmes-Adie pupil is due to a lesion of the ______ ______. Takes awhile to constrict the pupil. Parasymp. blocking agents constrict the pupil without effecting the normal one.
ciliary ganglion
197
Most visceral reflex fibers enter the spinal cord at the ______ and ______ levels.
cranial and sacral
198
Fibers from the visceral afferent nucleus (VAN) may project onto the ____ and _____ _______ neurons. Muscle spasm or increased muscle tone may result (visero-somatic pathway)
alpha and gamma motor neurons
199
Alpha motor neurons control __________ NMS and gamma motor neurons control ________ NMS.
extrafusal NMS
intrafusal NMS
200
GVA fibers terminate in the _____ ______ ______ and have connections with the GVE autonomic neurons:
- ILCC: Thoracolumbar (symp) nervous sys
- Sacral autonomic nucleus: craniosacral (para) nervous sys
visceral autonomic nucleus
201
Fibers from the visceral afferent nucleus may project onto the ________ for sympathetic response, or to parasympathetic nuclei in the brainstem or sacral spinal cord.
intermediolateral cell column
202
The gag and bladder reflex are both examples of _______-_______ pathways
visceral-visceral pathways
203
The spinoreticulothalamic pathways is an ascending visceral afferent pathway that conveys diffuse, poorly localized, persistent pain. Spinoreticular fibers terminate in nuclei of the brainstem reticular formation, which are involved in arousal, alertness, and activation of the ________ ________ _______ ________. Some fibers in this pathway may reach the centromedian nucleus of the thalamus and hypothalamus.
ascending reticular activating system (ARAS)
204
Which procedure is effective in eliminating sharp pain by severing the lateral spinothalamic tracts?
Anterolateral cordotomy
205
The prefrontal lobotomy is characterized by a change in pts behavior post surgery:
apathy
206
Some examples of referred pain include:
- MI-->_____ _____ ____
- Gall bladder--> _______ ______
left axillary region
| shoulder blade
207
Phantom limb phenomenon and phantom limb pain is when the pt still feels the limb being present, whether it is shortened or detached with a space between the stump and hand/foot. It may be due to the __________ of neuronal pools in the thalamus and cortex.
hypersensitivity
208
After years of programming from sensory input, the cortex occasionally remembers the amputated limb as still being there. A _____ _____ located in the stump may initiate episodes.
trigger zone
209
Nerve blocks to trigger points in the stump may be effective for treatment of _____ _____ ____.
phantom limb pain
210
The corticoreticulospinal pathway is formed by fibers in the premotor and prefrontal cortex that descend adjacent to the corticospinal tract and terminate in ________ and _______ reticular nuclei.
pontine and medually
211
The pontine reticular nuclei influence automatic movements of axial and limb mmm via the ______ ____________ _____.
medial reticulospinal tracts
212
The medullary reticular nuclei project descending influences to all levels of the psinal cord via the ______ _______ ______.
lateral reticulospinal tracts (LRST)
213
The LRST is the link for volitional control of _____ and _______.
bowel and bladder
214
Both the medial and lateral ____________ _____ have a similar influence upon posture and locomotion.
reticulospinal tracts
215
T/F: The newborn urinary bladder is in the abdomen and later descends into the pelvis. This is when the toddler can be potty trained and learn to control the bladder and bowel.
true!
216
Frontal lobe syndrome is when...
a person urinates without caring
217
Responses associated with the _______-______-spinal pathways include:
- modulation of cardiac fx
- pupillary dilation
- vasodilation
- perspiration
- shivering
- changes in GI and urinary fx
hypothalamo-reticulo-spinal pathways
218
In the brainstem, all GVA fibers (7, 9, 10) terminate in the ______ ______ _______.
nucleus tractus solitarius (NTS, solitary nucleus)
219
In the viscero-somatic pathway, the solitary nucleus projects info to the nucleus ambiguus. The response?
deglutition and cough (LER)
220
In the autonomic pathway, the solitary nucleus projects to the dorsal motor nucleus of V. The response?
cardiovascular, pulmonary, GI
221
During the LER (laryngeal expiratory reflex) cough epoch, closure of the lower esophageal sphincter, internal urethral sphincter, external urethral sphincter, anal sphincter, and inguinal canal must be synchronized with the increase in ____-________ ________.
intra-abdominal pressure (IAP)
222
Increases in IAP lead to increased risk of:
_______
_______ _______
_______ ___________
aspiration
gastric reflex
urinary incontinence (need internal sphincter tone!)
223
The muscle in the wall of the bladder is under parasympathetic control of S2-4. The external sphincter is innervated by ___ ______.
GSE fibers
224
As the bladder fills with urine, stretch receptors embedded in the bladder wall are activated.The pseudounipolar sensory neurons in the peripheral nerves send impulses through the dorsal root to the _______ ________ _____. Interneurons convey the stimulus to the _____ ________ ______ at S2-4. Efferent fibers from this nucleus stimulate mm. of the bladder to contract-->voiding.
visceral afferent nucleus
sacral autonomic nucleus
225
Atonic bladder is due to lesions of the _____ _____ __ ____ or ______ ______. Results in flaccid bladder and increased bladder capacity. Voluntary voiding is possible, but incomplete.
dorsal roots of S2-4
| dorsal funiculi
226
Reflex bladder: Transection of the spinal cord above S2 interrupts the_____ ________ ______ to the_____ _______ _____, and the patient is unable to voluntarily void his bladder (i.e., there is urinary retention). After spinal shock, the bladder reflex may return without voluntary control, and the patient will have automatic reflex voiding or a reflex bladder.
lateral reticulospinal tracts
sacral autonomic nucleus
227
```
Bladder reflex:
stretch receptors in bladder wall->
afferent neurons at S2-4->
Visceral afferent nucleus at S2-4->
sacral autonomic nucleus at S2-4->
Efferent neurons at S2-4->
Response?
```
voiding or increased bladder done
228
In both atonic and reflex bladder, the pt must be _________.
catheterized
229
Pt presents with...Dx?
- progressive deafness in the left ear
- Nystagmus
- Anesthesia of the left face
- Inability to close the left eye
- Drooping of the L corner of the mouth
- Broad-based, weaving gait
Acoustic neurinoma
unilateral deafness, bell’s palsy, trigeminal n. lesion, cerebellar dysfunction
230
Pt presents with....Dx?
- right foot drop
- progressive gait deterioration-->ataxia
- mild weakness in hands
- atrophy of tongue with dysarthria and dysphagia (CN 12)
- bilateral weakness of the proximal mm. of lower extremity
- Distal mm. of upper extremity mildly weak with some atrophy
- DTR hyperreflexic
- Babinksi + bilaterally
- Denervation of the distal mm of upper and lower extremity
ALS
231
Pt presents with...dx?
CC: radiating pains in his legs and back
-both legs hypersensitive to touch
-light stroking of legs produced radiating pains
-bilat. loss of proprio, 2 pt, of lower limbs
-bilaterally loss of patellar and achilles reflex
-bilat. hypotonia of lower limb mm.
-wide based gait with slapping of feet
-swaying when eyes closed
-atonic bladder and retention of urine
Tabes dorsalis
NO ANT HORN PROBLEM! NO LMN LESION! Anterior horn no where near post. column…the motor issues are from the dorsal roots
What caused the radiating pains….neuromeningovascular infx of dorsal roots and posterior columns, irritated dorsal roots affects the fast pain fibers, which become irritated, leading to hyperactive pain fibers=radiating pains.
232
Pt presents with...Dx?
- dilated left pupil
- right sided throbbing headaches
- left didn’t react directly or consensually
- right pupil=accommodation but left remained relaxed, left pupil slowly constricted upon convergence
- methacholine eye drops: right unaffected, left pupil constricted
Holmes-addie pupil
233
TQ: Pt presents with...Dx?
CC: abrupt onset of paralysis on left side of body and blind left eye
-Left hemiparesis
-Hypertonia and hyperreflexia of the left upper and lower limbs
-Left Babinski
-Paralysis of the mimetic muscles on the lower left side of the face
-Left homonymous hemianopsia.
lesion of the R optic tract (overlies cerebral peduncle so also affects corticospinal and corticobulbar fibers that run within it--> leading to contralateral spastic hemiplegia and contralateral supranuclear facial palsy)
