Chapter 5: The Brain Stem Flashcards
1
Q
Label the figure.
A
Brain Inferior View
2
Q
Which cranial nerves arise from the midbrain?
A
CN III and IV
oculomotor and trochlear
3
Q
Which cranial nerves enter or exit from the pons?
A
CN V, VI, VII, and VIII (trigeminal, abducens, facial, and vestibulocochlear)
4
Q
Which nerves enter and exit from the medulla?
A
CN IX, X, and XII (glossopharyngeal, vagus, and hypoglossal nerves)
5
Q
Where are motor nuclei located in the brainstem in general?
A
more medially
6
Q
Where are sensory nuclei located in the brainstem in general?
A
more laterally
7
Q
Which CN in the brainstem are purely motor?
A
CN III, IV, VI, XII
( oculomotor, trochlear, abducens, hypoglossal)
8
Q
Which CN in the brainstem have a sensory component?
Which ones are mixed?
A
laterally located ones CN V, VII, IX, X
trigeminal, facial, glossopharyngeal, vagus respectively
9
Q
Does CN IV exit from the dorsal or ventral part of the brainstem?
A
dorsal
10
Q
Is CN VII sensory or motor?
A
mixed
11
Q
Label the image and distinguish which section of the brainstem it is from.
A
Upper midbrain level of nerve III
12
Q
Label the image and distinguish which section of the brainstem it is from?
A
lower midbrain: level of nucleus CN IV
13
Q
Label the image and distinguish which section of the brainstem it is from?
A
Middle pons level of nerve V
14
Q
Label the image and distinguish which part of the brainstem it is from.
A
Lower pons; level of nerves VI and VII
15
Q
Label the image and distinguish which part of the brainstem it is from?
A
open medulla
16
Q
Label the image and determine which part of the midbrain it is from.
A
closed medulla; lower medulla
17
Q
CN I name.
A
olfactory nerve
18
Q
CN I type.
A
sensory
19
Q
CN I function.
A
smells
20
Q
Result of CN I lesion.
A
anosmia
21
Q
CN II name.
A
optic
22
Q
CN II type.
A
sensory
23
Q
CN II function.
A
sees
24
Q
Result of a CN II lesion.
A
- visual field deficits (anopsia)
- loss of light reflex with III
- only nerve to be affected by MS
25
CN III name.
oculomotor
26
CN III type.
motor
27
CN III function.
* innervates SR. IR, MR, IO extraoculuar muscles: adduction (MR) most important action
* raises eyelid (levator palpebrae superioris)
* constricts pupil (sphincter pupillae)
* accommodates (ciliary muscle)
28
What are characteristics of lesions of the oculomotor nerve?
* diplopia, external strabismus
* loss of parallel gaze
* ptosis
* dilated pupil, loss of light reflex with II
* loss of near response
29
CN IV name.
trochlear
30
CN IV type.
motor
31
CN IV function
superior oblique- depresses and abducts eyeball (makes eyeball look down and out)
intorts
32
Lesion of CN IV?
* weakness looking down with adducted eye
* trouble going down stairs
* head tilts away from lesioned side
33
CN V name?
trigeminal nerve
34
V1 branch of trigeminal nerve name.
ophthalmic
35
V2 branch of trigeminal nerve name.
maxillary (V2)
36
V3 branch of trigeminal nerve name?
mandibular
37
What type of nerve is the trigeminal nerve?
mixed
38
Function of the trigeminal nerve?
* general sensation (touch, pain, temperature) of forehead/ scalp/ cornea
* general sensation of palate, nasal cavity, maxillary face, maxillary teeth
* general sensation of anterior two-thirds of tongue, mandibular face, mandibular teeth
* motor to muscles of mastication (temporalis, masseter, medial and lateral pterygoids) and anterior belly of digastric, mylohyoid, tensor tympani, tensor palati
39
Results of lesions of the trigeminal nerve V1?
loss of general sensation in skin of forehead/ scalp
loss of blink reflex with VII
40
Results of V2 nerve lesion.
loss of general sensation in skin over maxilla, maxillary teeth
41
Results of V3 lesion.
* loss of general sensation in skin over mandible, mandibular teeth, tongue, weakness in chewing
* jaw deviation toward weak side
* trigeminal neuralgia - intractable pain in V2 or V3 territory
42
What is the name for CN VI?
abducens
43
CN VI type.
motor
44
CN VI function?
lateral rectus - abducts eyeball
45
Result of lesions to CN VI?
* diplopia, internal strabismus
* loss of parallel gaze "pseudoptosis"
46
What is CN VII name?
facial
47
What type of CN is CN VII?
mixed
48
What is the function of CN VII?
* to muscles of facial expression, posterior belly of digastric, stylohyoid, stapedius
* salivation (submandibular, sublingual glands)
* skin behind ear
* taste in anterior 2/3 of tongue/ palate
* tears (lacrimal gland)
49
What are the results of lesions of the facial nerve?
* corner of mouth droops, can't close eye, cannot wrinkle forehead, loss of blink reflex, hyperacusis, Bells palsy - lesion of nerve in facial canal
* pain behind ear
* alteration or loss of taste (ageusia)
* eye dry and red
50
CN VIII name?
vestibulocochlear
51
CN VIII nerve type?
sensory
52
What is the function of CN VIII
* hearing
* angular acceleration (head turning)
* linear acceleration (gravity)
53
What are the results of lesions of CN VIII lesion?
* sensorineural hearing loss
* loss of balance, nystagmus
54
What is the name of CN IX?
glossopharyngeal
55
What is the nerve type of CN IX?
mixed
56
What is the function of CN IX?
* oropharynx sensation, carotid sinus/ body
* salivation (parotid gland)
* all sensation of posterior one-third of tongue
* motor to one muscle - stylopharyngeus
57
What is the result of a lesion to CN IX?
loss of gag reflex with X
58
What is the name for CN X?
vagus
59
What type of nerve is the vagus nerve?
mixed
60
What is the function of the vagus nerve?
* to muscles of palate and pharynx for swallowing except tensor palati (V) and stylopharyngeus (IX)
* to all muscles of larynx (phonates)
* sensory of larynx and laryngopharynx
* sensory of GI tract
* to GI tract smooth muscle and glands to foregut and midgut
61
Results of lesions to vagus?
* nasal speech, nasal regurgitation
* dysphagia, palate droop
* uvula pointing away from affected side
* hoarseness/ fixed vocal cord
* loss of gag reflex with IX
* loss of cough reflex
62
What is the name for CN XI?
Accessory
63
What type of nerve is CN XI?
motor
64
What are the functions of CN XI?
* head rotation to opposite side (sternocleidomastoid)
* elevates and rotates scapula (trapezius)
65
Results of a lesion to XI?
* weakness turning chin to opposite side
* shoulder droop
66
What is the name for CN XII?
hypoglossal
67
What type of nerve is the hypoglossal nerve?
motor
68
What is the function of CN XII?
* tongue movement
(styloglossus, hyoglossus, genioglossus, and intrinsic tongue muscles - palatoglossus is by X
69
What are the result of a lesion to CN XII?
tongue pointing toward same (affected side on protrusion)
70
Lesions of ML (medial lemniscus in any part of the brainstem lead to what sensory deficits?
contralatera loss of discriminative touch, vibration, pressure, and conscious propioception
71
What is the medial longitudinal fasciulus?
fiber bundle interconnecting centers for horizontal gaze, the vestibular nuclei, and the nerve nuclei of CN III, IV, and VI which innervate sk. muscles that move the eyeball
72
Descending hypothalamic fibers course with what fibers in the lateral part of the brainstem?
spinothalamic fibers
73
Where are the olives of the medulla located?
lateral to the pyramids in the rostral two-thirds of the medulla
74
What do the olives of the medulla contain?
convoluted inferior olivary nuclei. The olivary nuclei send climbing (olivocerebellar) fibers into the cerebellum through the inferior cerebellar peduncle.
75
Where is the spinal nucleus of V located in the medulla?
position analogous to the dorsal horn of the spinal cord
76
Where is the spinal tract of V located in the medulla?
just lateral to the spinal nucleus of V and extends from the upper cervical cord (C2) to the point of entry of the fifth cranial nerve in the pons
77
What is the spinal tract of V?
central processes from cells in the trigeminal ganglion conveying pain and temperature sensations from the face enter the brain stem in the rostral pons bud descend in the spinal tract of CN V and synapse on cells in the spinal nucleus
78
What axons does the solitary nucleus receive?
axons of all general and special visceral afferent fibers carried into the CNS by CN VII, IX, and X. These include taste, cardiorespiratory, and GI sensations carried by these cranial nerves
79
Where is the nucleus ambiguus located in the medulla?
dorsal to the inferior olive
80
How will a unilateral lesion of the nucleus ambiguus affect the uvula? (Where will it deviate?)
away from the lesioned nerve
81
What axons are located in the nucleus ambiguus?
the ninth and tenth CN
82
Where is the dorsal motor nucleus of CN X located in the medulla?
| In relation to hypoglossal nucleus
lateral to the hypoglossal nucleus in the floor of the fourth ventricle
83
What is purpose of fibers in the dorsal nucleus of X?
major parasympathetic nucleus of the brain stem, and it supplies preganglionic fibers innervating terminal ganglia in the thorax and the foregut and midgut parts of the Gi tract
