B7.025 Cranial Nerve Intro Flashcards
1
Q
how are CNs numbered
A
roman numerals in a rostrocaudal direction as they exit the brainstem
2
Q
CN I
A
olfactory
3
Q
CN II
A
optic
4
Q
CN III
A
oculomotor
5
Q
CN IV
A
trochlear
6
Q
CN V
A
trigeminal
7
Q
CN VI
A
abducens
8
Q
CN VII
A
facial
9
Q
CN VIII
A
vestibulocochlear
10
Q
CN IX
A
glossopharyngeal
11
Q
CN X
A
vagus
12
Q
CN XI
A
spinal accessory
13
Q
CN XII
A
hypoglossal
14
Q
mnemonic for CN names
A
on old Olympus towering top a French and german viewed some hops
15
Q
possible components of cranial nerves
A
sensory (afferent)
motor (efferent)
autonomic (efferent)
less standardized than spinal nerves
16
Q
just sensory CNs
A
I, II, VIII
17
Q
just motor CNs
A
III, IV, VI, XI, XII
18
Q
motor / sensory CNs
A
V, VII, IX, X
19
Q
pathway description of purely sensory CNs
A
- carry information into CNS (afferent)
- neuronal cell body is in or near periphery (usually a ganglion)
- central axons will synapse on a neuron in the CNS, usually in the brainstem (sensory relay nucleus)
20
Q
main functions of CN I
A
olfaction
21
Q
main functions of CN II
A
vision
22
Q
main functions of CN III
A
eye movements
pupil constriction
23
Q
main functions of CN IV
A
eye movements
24
Q
main functions of CN V
A
facial sensation
muscles of mastication
25
main functions of CN VI
eye movements
26
main functions of CN VII
muscles of facial expression
taste (anterior 2/3)
lacrimation
salivation
27
main functions of CN VIII
hearing
| equilibrium sense
28
main functions of CN IX
pharyngeal muscles (nbd)
carotid body reflexes
salivation
29
main functions of CN X
parasympathetics to most organs
laryngeal muscles (voice)
pharyngeal muscles (swallowing)
aortic arch reflexes
30
main functions of CN XI
head turning (sternomastoid and trapezius)
31
main functions of CN XII
tongue movement
32
course of CN I
sensory neurons in nasal epithelium
| axons synapse in olfactory bulb
33
damage to CN I
anosmia (lack of smell)
34
course of CN II
sensory neurons in retina (a lot of processing activity takes place here, skips its synapse in the brainstem)
axons synapse in the thalamus
35
damage to CN II
visual field deficits
36
course of CN VIII
sensory neurons in the vestibular ganglion (balance) or auditory ganglions (hearing)
-hair cells
axons synapse in brainstem (vestibular or cochlear nuclei)
37
damage to CN VIII
hearing loss or balance disorder
38
pathway description of purely motor CNs
1. nerves carry information away from the CNS (efferent)
2. neuronal cell body (motor neuron) is found in a nucleus in the brainstem; they are analogous to motor neurons in the ventral horn
3. synapse on muscles in the periphery
39
CNs with parasympathetic preganglionic (efferent) axons
III - pupillary constriction, lens accommodation
VII - salivation, lacrimation
IX - salivation
X - visceral function, heart rate
40
eye muscles innervated by CN III
```
levator palpebrae (lid)
superior rectus
medial rectus
constrictor pupillae (para)
inferior rectus
inferior oblique
```
41
eye muscles innervated by CN IV
superior oblique
42
eye muscles innervated by CN VI
lateral rectus
43
course of CN III, IV, VI
motor neurons are located in brainstem nuclei
| parasympathetic neurons are located in brainstem ganglion
44
damage to CN III, IV, VI
deficits in eye movement, diplopia
III - eye moves down and out, large pupils
IV - mostly compensated by other muscles, subtle, slight eye roll
VI - medial deviation of eye
45
course of CN XI
innervated upper trapezius and sternocleidomastoid
| motor neurons located in the spinal cord (C1-5)
46
damage to CN XI
inability to shrug shoulders, turn head
47
course of CN XII
innervated the intrinsic tongue muscles
| motor neurons located in the hypoglossal nucleus
48
damage to CN XII
abnormal tongue protrusion
49
CN V divisions
V1 - ophthalmic
V2 - maxillary
V3 - mandibular
50
sensory component of CN V
somatic sensation for the face
cell bodies in trigeminal ganglion
synapse in spinal trigeminal or principal sensory nuclei
51
motor component of CN V
innervate muscles of mastication (tensor palati, tensor tympani)
cell bodies in trigeminal motor nucleus
52
damage to CN V
facial numbness
| difficulty chewing
53
sensory component CN VII
taste (anterior 2/3)
a little touch
cell bodies in geniculate ganglion, synapse in solitary nucleus or in spinal trigeminal nucleus
54
motor component of CN VII
motor nerves innervate muscles of facial expression, stapedius muscle
cell bodies in facial nucleus
55
parasympathetic component of CN VII
innervate salivary, lacrimal, nasal glands
| cell bodies in superior salivatory nucleus
56
damage to CN VII
facial paralysis
loss of taste
parasympathetic dysfunction
57
sensory component of CN IX
touch back of tongue, pharynx, ear
taste back of tongue
visceral heart
cell bodies in ganglia, synapse in spinal nucleus V or solitary nucleus
58
motor component of CN IX
innervate stylopharyngeous muscle; cell bodies in nucleus ambiguus
59
parasympathetic component of CN IX
innervate parotid gland, cell bodies in inferior salivatory nucleus
60
damage to CN IX
loss of taste
mouth sensory loss (gag)
salivary function
61
sensory component of CN X
mostly visceral afferents
a few afferents for taste and sensation
cell bodies in vagal ganglia, synapse in solitary nucleus or spinal trigeminal nucleus
62
motor component of CN X
most muscles of the larynx, pharynx, palate
| cell bodies in the nucleus ambiguus
63
parasympathetic component of CN X
innervate viscera in thorax and abdomen, cell bodies in dorsal motor nucleus of the vagus
64
damage to CN X
diminished gag (motor)
hoarseness
difficulty swallowing
