(7) Cranial Nerves Flashcards
(169 cards)
1
Q
mnemonic to remember cranial nerve names
A
On = Olfactory Occasion= Optic Our= Oculomotor Trusty = Trochlear Truck= Trigeminal Acts = Abducens Funny= Facial Very= Vestibulocochlear Good= Glossopharyngeal Vehicle= Vagus Any= Accessory How= Hypoglossal
2
Q
mnemonic to remember sensory/motor/both of cranial nerves
A
Some= olfactory Say= optic Money= oculomotor Matters= trochlear But= trigeminal My= abducens Brother= facial Says= vestibulocochlear Big= glossopharyngeal Brains= vagus Matter= accessory Most= hypoglossal
3
Q
3 different types of nerves
A
sensory (afferent) vs motor (efferent)
somatic vs visceral
general sensory vs special sensory
4
Q
general sensory vs special sensory example
A
general= pain, temperature, touch, proprioception
special= vision, hearing, smell (NOT TASTE)
5
Q
6 nerve types
A
somatic sensory (Ss)-- sensations from face special sensory (Sp) -- smell, vision, hearing somatic motor (Sm)-- extraocular muscles (innervate skeletal muscle)
Visceral sensory (Vi)-- gut distension, taste visceral motor (A)-- salivary gland pharyngeal (P) -- facial muscle
6
Q
most skeletal muscle of the body is derived from…
A
myotomes
7
Q
innervation of myotomes is
A
somatic motor
8
Q
some skeletal muscle in the head and neck are derived from…
A
branchial (gill) arches
innervation is pharyngeal motor (P)
- give rise to muscle of facial expression, chewing, jaw
9
Q
what are ganglia?
A
similar structure and function
outside CNS (in PNS)
10
Q
2 neuron chain of general visceral efferents (autonomics)
A
- preganglionic neuron projects to ganglion; synapses (acetycholine) onto post ganglionic neuron
- post ganglionic neuron projects to target
11
Q
general visceral efferents arise entirely from…
A
spinal cord
12
Q
general visceral efferents sympathetics emerge from
A
intermediate horn spinal cord (T2-L3) and travel through sympathetic chain
13
Q
general visceral efferents sympathetics synapse..
A
either within chain or abdominal or pelvic ganglia
14
Q
preganglionic and postganglionic length of general visceral efferents sympathetics
A
preganglionic= short
post-ganglionic= long
15
Q
post ganglionic neurotransmitter
general visceral efferents sympathetics
A
noradrenaline
16
Q
is there a sympathetic component of cranial nerves?
A
NO sympathetic component
17
Q
general visceral efferents parasympathetics emerge from
A
- principle supply from cranial nerves
- part of some cranial nerves (and sacral spinal nerves)
18
Q
general visceral efferents parasympathetics length of pre/post ganglionic
A
pre-ganglionic= long
post-ganglionic= short
19
Q
post ganglionic neurotransmitter
general visceral efferents parasympathetics
A
acetycholine
20
Q
preganglionic portiosn of general visceral efferents parasympathetics found where?
A
at specific nucleus in brainstem, or found in grey matter of lowest levels of the spinal cord (S2-S4)
21
Q
what is CN I
A
Olfactory nerve
22
Q
is CN I sensory/motor/both
A
sensory only
23
Q
what type of sensory is CNI
A
special sensory (Sp)
- olfaction and smell
24
Q
multiple elements of CNI passes from…
A
olfactory epithelium through skull to reach olfactory bulb where it synapses
25
what is CNII
Optic nerve
26
is CN II sensory/motor/both
sensory only
27
what type of sensory is CNII
Special sensory (Sp)
- vision from retina
28
CNII fibers cross where? terminate?
some fibers cross at optic chiasma
- terminate in thalamus (LGN), midbrain (superior colliculus), and hypothalamus
29
what is CNIII
oculomotor
30
is CNIII sensory/motor/both
motor only
31
what type of motor is CNIII
somatic motor (Sm)
Visceral Motor (A)
32
somatic motor of CNIII
- most extraocular eye muscles (medial, superior, inferior recti; inferior oblique; levator palpebrae superioris)
33
visceral motor of CNIII
pupil diameter
| - constriction, parasympathetic
34
CNIII emerges from...
anterior, rostral midbrain
35
damage to CNIII results in
eye movement problems
36
6 muscles the produce eye movement
- superior rectus
- lateral rectus
- medial rectus
- inferior rectus
- superior oblique
- inferior oblique
37
6 different eye movements
```
adduction
abduction
elevation
depression
extorsion
intorsion
```
38
what is adduction eye movement & what muscle
pupil toward midline/nose
- medial rectus
39
what is abduction eye movement & what muscle
pupil away from nose (temporally)
- lateral rectus
40
what is elevation eye movement & what muscle
move pupil up within orbit
- superior rectus + inferior oblique
41
what is depression eye movement & what muscle
move pupil down within orbit
- inferior rectus + superior oblique
42
what is extorsion eye movement
pupil rotate away from midline
43
what is intorsion eye movement
pupil rotate toward midline
44
levator palpebrae superioris contributes to
elevation of the upper eyelid
45
weakness of levator palpebrae results in (what is it called)
weakness of muscle or loss of innervation leads to droopy eye lid called ptosis
46
oculomotor nerve carries... (pre/post ganglionic)
preganglionc parasympathetics to the ciliary ganglion
post-ganglionic carried by the short ciliary nerve to the eye
47
what is CN IV
Trochlear
48
is CN IV sensory/motor/both
Motor only
49
what type of motor CN IV
somatic motor (Sm)
- extraocular eye muscles (nerve supply for superior oblique)
movement of eyeball
50
CN IV emerges from
posterior caudal midbrain/rostral pons
51
what makes CN IV special?
only nerve that emerges from posterior of brainstem
52
damage to CN IV results in?
when ask for depression (move down in orbit), eye deviates from midline
53
what is CN V
trigeminal nerve
54
is CN V sensory/motor/both
BOTH
55
what motor and sensory is CN V?
pharyngeal (P)
somatic sensory (Ss)
56
pharyngeal CNV (2)
(motor)
- muscles of mastication (chewing)
- inner ear muscle (tensor tympani)
57
somatic sensory of CN V (2)
- sensation (pain, temperature, touch, conscious proprioception) from face, scalp, cornea, nasal and oral cavity, anterior 2/3 tongue, dura (surrounding brain)
- unconscious proprioception (muscles of mastication)
58
where does CN V emerge from?
lateral pons, mid-pons
59
4 muscles of mastication
temporalis
masseter
medial pterygoids
lateral pterygoids
60
sensory fibers of trigeminal nerve are distributed to surface of face in what 3 divisions?
ophthalmic division
maxillary division (cheek bones)
mandibular division (lower jaw, teeth)
61
what is tensor tympani
muscle that attaches to tympanic membrane directly
tympanic membrane (where the ear canal terminates-- the eardrum)
62
what is the function of tensor tympani?
dampen nose of chewing
- when tensed, muscle pulls the malleus medially, tensing tympanic membrane and damping vibration in the ear ossicles
- reducing perceive amplitude of sounds
63
what is CN VI?
abducens nerve
64
is CN VI sensory/motor/both
motor only
65
what type of motor is CN VI?
somatic motor (Sm)
- extraocular eye muscles (lateral rectus muscle)
66
damage to CN VI results in??
loss of function/weakness in lateral rectus, difficult move eye laterally
67
CN VI emerges from
caudal pons, medial
68
what is CN VII?
facial nerve
69
is CN VII sensory/motor/both
BOTH
70
what type of sensory and motor is CN VII
motor: pharyngeal, visceral motor
sensory: visceral sensory, somatic sensory
71
pharyngeal CN VII
muscles of facial expression
inner ear muscle (stapedius)
72
visceral motor CN VII
salivary glands (submandibular sublingual) via submandibular ganglia
lacrimal glands (tears) via pterygopalatine ganglia
(parasympathetic) -- increases saliva and tear production
73
visceral sensory CN VII
anterior 2/3 tongue (Taste)
74
somatic sensory CN VII
skin of outer ear
75
CN VII emerges from
caudal pons, lateral
76
2 functions of muscles of facial expression?
- make you smile, frown, close eyes tightly
| - many muscles innervated by facial nerve
77
function of the stapedius
dampens the vibrations of the stapes by pulling on the neck of that bone
- help control amplitude of sound waves
- dampens ability of stapes vibration and protects inner ear from high noise levels (own voice volume)
78
what is CN VIII
vestibulocochlear nerve
79
is CN VIII sensory/motor/both
sensory only
80
what type of sensory is CN VIII
special sensory (Sp)
balance and hearing
81
CN VIII emerges from?
caudal pons, lateral
82
what part of ear detects gravity
semicircular canals (part of vestibular apparatus), info is collected by vestibular nerve
- detects gravity, direction of head in space
83
what is CN IX
glossopharyngeal nerve
84
is CN IX sensory/motor/both
both
85
motor and sensory components of CN IX
motor: pharyngeal, visceral motor
sensory: visceral sensory, somatic sensory
86
pharyngeal component of CN IX
- stylopharyngeus (swallowing)
87
visceral motor component of CN IX
```
parotid gland (salivation)
- parasympathetic
```
88
visceral sensory component of CN IX (3)
- taste fibers posterior 1/3 of tongue
- pharynx sensation (gag reflex) -- afferent limb
- carotid body/sinus
89
somatic sensory component of CN IX (3)
- general sensation of posterior 1/3 of tongue
- ear: inner tympanic membrane
- outer ear skin
(pain, temperature)
90
visceral motor of CN IX pre/post-ganglionics
pre= synapse to otic ganglia
post= travel to parotid gland (salivary gland)
- stimulates saliva
91
visceral sensory of CN IX carotid body/sinus
body= chemoreceptors monitoring blood O2, CO2, and pH
Carotid sinus: baroreceptors monitoring blood pressure
- higher control of cardiac function
- sensory info carried by glossopharyngeal nerve
92
what is CN X?
vagus nerve
93
is CN X sensory/motor/both?
both
94
motor and sensory components of CN X
motor: pharyngeal, visceral motor
sensory: somatic sensory, visceral sensory
95
CN X pharyngeal component
muscles in pharynx, larynx, and upper esophagus
- speech and swallowing, gag reflex (Efferent limb)
96
CN X visceral motor component
- parasympathetic control of thoracic (lungs/heart) and abdominal viscera (stomach, intestine etc)
- principle parasympathetic control**
97
somatic sensory of CN X
- general sensation: external ear, innervate external tympanic membrane
98
visceral sensory of CN X (2)
- sensation from viscera; larynx, esophagus, gut
| - aortic bodies (chemoreceptors, baroreceptors)
99
CN X emerges from
mid medulla, laterally
100
vagus nerve delivers pre ganglionic parasympathetic to
ganglia on target organs
- go to structures in thorax and abdomen
101
post-ganglionic vagus nerve located
within the target tissue, within walls/structure of visceral structures
102
what is CN XI
accessory nerve
103
is CN XI sensory/motor/both
motor only
104
motor component of CN XI
pharyngeal
- sternocleidomastoid and trapezius muscles
- movement of head and shoulders
105
CN XI is formed by
rootlets from cervical spinal cord
106
what is CN XII
hypoglossal nerve
107
is CN XII sensory/motor/both
motor only
108
motor component of hypoglossal nerve
somatic motor
- muscles of tongue
- movement of tongue
109
CN XII emerges from
medulla, laterally (more anterior)
110
which 3 nerves are purely special sensory
CNI olfactory
CNII optic
CN IX vestibulocochlear
111
which nerve is both somatic and visceral motor
CN III oculomotor
112
what 5 nerves are purely motor
```
CN II optic - extraocular eye muscles
CN III oculomotor - extraocular eye muscles
CN VI abducens- extraocular eye muscles
CN XI accessory
CN XII hypoglossal
```
113
what 4 nerves are both motor and sensory
CN V trigeminal
CN VII facial
CN IX glossopharyngeal
CN X vagus
114
cranial nerve nuclei are organized into ....
functional columns
115
at what levels of the spinal cord is somatic present??
every level
116
at what levels of the spinal cord is visceral present?
thoracic and sacral
117
what type of nerve is most medial?
somatic motor
| motor=medial
118
what type of nerve is most lateral?
special sensory
| sensory=lateral
119
cranial nerve nuclei compact and restricted to a...
restricted (rostral-caudal) to a sub-region of a single level of brainstem
- typically near the level where nerve emerges/enters the brainstem
120
caudal medulla at pyramidal decussation what cranial nerve nucleus is present?
- associated with what nerve?
somatic sensory nucleus associated with trigeminal nerve
121
the trigeminal sensory nucleus extends where?
extends full length of the brainstem
122
trigeminal sensory nucleus 3 components
- spinal trigeminal nucleus (lower part)= medulla + pons
- main sensory nucleus (where nerve connects)= pons
- mesencephalic nucleus (upper part)= pons + midbrain
123
3 somatic sensory modalities of spinal trigeminal nucleus
crude touch, pain and temperature
- spinothalamic tract
124
2 somatic sensory modalities of
discriminative touch and conscious proprioception
- dorsal column medial lemniscus pathway
125
somatic sensory modality of mesencephalic nucleus
unconscious proprioception
- associated with muscles of mastication
- spinocerebellar pathways
126
CN V primary neuron 2 locations
in the trigeminal ganglion (of spinal trigeminal nucleus)
and the mesencephalic nucleus
127
output from the spinal and main nuclei do what?
cross and enter the spinothalamic tract and medial lemniscus
- travel to the thalamus (ventral posterior nucleus)
- then to somatosensory cortex
128
mesencephalic nucleus projections go to
trigeminal motor nucleus providing proprioceptive feedback (and reflexes) for muscles of mastication
- also projections to the cerebellum (trigeminocerebellar fibres) via the inferior cerebellar peduncle
129
caudal medulla (caudal to the obex) is dominated by (what 2 things)
SpVn = spinal trigeminal nucleus
SpVtr= spinal trigeminal tract
130
what is the hypoglossal nucleus
somatic motor (most medial)
131
what is the vagas nerve nucleus (autonomic)
dorsal motor nucleus of the vagus
- autonomic( parasympathetic)
132
solitary nucleus and tract
- carries fibres for what 3 cranial nerves?
visceral sensory
- tract carries fibers from CN VII (facial), IX (glossopharyngeal), X (vagus)
133
solitary nucleus projects to
ventral posterior nucleus and hypothalamus (ipsilateral)
via the central tegmental tract
134
visceral sensory info from solitary nucleus is carried by..
central tegmental tract to the thalamus
135
at the caudal pons, fibers for what cranial nerves are present?
fibers for abducens (CN VI) and facial nerves (CNVII)
136
at the caudal pons what 2 cranial nerve nuclei are present
- facial motor nucleus (pharyngeal)
| - abducens nucleus (somatic motor)
137
course of projections from the facial nucleus
projections go first posterior and rostral, then hair pin turn and wraps around abducens nucleus to exit the brainstem
- turn gives rise to the facial colliculus, and is formed by internal genu
138
internal genu of the facial nerve are the... and form the....
they are the most posterior fibers
produce facial colliculus
139
what 3 trigeminal nerve nuclei are present at mid pons
- main nucleus
- mesencephalic nucleus (unconscious proprioception)
- motor nucleus (pharyngeal)- muscles of mastication
140
what cranial nerve nuclei is present at the rostral pons
continuation of mesencephalic nucleus of the trigeminal nerve (CN V)
141
what cranial nerve nuclei is present at the caudal midbrain
trochlear nucleus (trochlear nerve, CN IV)
somatic motor, medially located
142
what is so special about the trochlear nerve nuclei
it is the only CN with motor nucleus that decussates, and exits posterior margin
143
4 somatic motor nerve nuclei
```
oculomotor nucleus (CN III)
trochlear nucleus (CN IV)
abducens nucleus ( CN VI)
hypoglossal nucleus (CN XII)
```
144
where is the medial longitudinal fissure located
always present at midline
connects nuclei associated with eye movements
- CN III (oculomotor)
- CN IV (optic)
- CN VI (abducens)
145
4 pharyngeal nerve nuclei
Trigeminal motor nucleus (CN V) - mid pons
facial motor nucleus (CN VII) - caudal pons
nucleus ambiguus (glossopharyngeal, vagus)
accessory nucleus (CN XI)
146
5 autonomic parasympathetic nerve nuclei
- nucleus of edinger westphal (CN III oculomotor)
- superior salivary nucleus (CN VII facial)
- inferior salivary nucleus (CN IX glossopharyngeal)
- dorsal motor nucleus of the vagus (CN V)
- nucleus ambiguus (CN X vagus)
147
nucleus of edinger westphall
CN III (oculomotor)
innervation of iris via ciliary ganglia
148
superior salivary nucleus
CN VII (facial)
innervation of lacrimal gland via pterygopalatine ganglia and submandibular gland via submandibular ganglia
149
inferior salivary nucleus
CN IX (glossopharyngeal)
- innervation of parotid gland via otic ganglia
150
exception to rule of one nucleus, one functional type
- pharyngeal/branchiomeric component
| - autonomic component
151
visceral sensory of the solitary nucleus and tract
found in medulla, tract extending from pons
- taste sensation mediated by upper portion of solitary nucleus
- viscera = lower part of nucleus
152
primary visceral sensory neurons for CN VII found in...
geniculate ganglion
153
primary visceral sensory neurons for CN IX found in
inferior ganglion of IX
154
primary visceral sensory neurons for CN X found in
inferior ganglion of X
155
what are considered visceral sensations?
blood pressure, blood oxygen level
156
primary somatic sensory neurons for CN V are located in (2)
trigeminal ganglia and mesencephalic nucleus
157
fibers from CN VII, IX and X project to the ...
spinal nucleus and the main sensory necleus via the spinal tract
- skin of the ear
158
CN VII primary somatic sensory neuron
geniculate ganglion
- project to spinal trigeminal nucleus
(from outer ear)
159
CN VII primary visceral sensory neuron
geniculate ganglion
- project to solitary nucleus, travel with tract
(taste buds anterior 2/3 tongue)
160
CN VII pharyngeal nucleus
facial motor nucleus (does loop)
- muscles of facial expression and stapedius
161
CN VII visceral motor nucleus
to salivary, nasal and palatine and lacrimal glands (via submandibular and pterygopalatine ganglia)
- superior salivary nucleus give rise to preganglionic fibers to ganglia that innervate salivary and lacrimal glands
162
CN IX primary somatic sensory neuron
superior ganglia of IX
| - project ot spinal trigeminal nucleus
163
CN IX primary visceral sensory neuron
inferior ganglion of IX
2 visceral sensory
- taste buds posterior 1/3 tongue
- carotid body, and sinus, mucosa, pharynx, posterior tongue, middle ear (travel to solitary nucleus)
164
CN IX brachial motor (pharyngeal) nucleus
nucleus ambiguus
165
CN IX visceral motor projects to
parotid glands via otic ganglion
166
CN X primary somatic sensory nuclei
superior ganglion of X
| outer ear
- project to spinal trigeminal nucleus
167
CN X primary visceral sensory nuclei
inferior ganglion of X
2 visceral sensory
- from epiglottal taste buds
- from larynx, pharynx, thorax, abdomen
168
CN X brachial motor projects to
larynx and pharynx
169
CN X visceral motor 2 components
thorax and abdomen
