Cranial Nerves Flashcards
1
Q
What are cranial nerves and what system are they a part of
A
bundle of sensory OR motor axons
part of peripheral nervous system
2
Q
why are cranial nerves named how they are? what are they covered in?
A
called cranial because they emerge through foramina or fissures in the cranium
they are covered by sheaths derived fringe the cranial membranes (meninges)
3
Q
what cranial nerves do NOT originate from the brain stem
A
CN 1, CN II, and CN XI
4
Q
Cranial nerve names pneumonic
A
Oh Oh Oh To Touch And Feel Very Good Velvet Ahh Heaven
5
Q
what is CN I
A
olfactory
6
Q
what is CN II
A
Optic
7
Q
what is CN III
A
oculomotor
8
Q
what is CN IV
A
trochlear
9
Q
what is CN V
A
trigeminal
10
Q
what is CN VI
A
Abducens or Abducent
11
Q
what is CN VII
A
facial
12
Q
what is CN VIII
A
vestibulocochlear
13
Q
what is CN IX
A
glossopharyngeal
14
Q
what is CN X
A
vagus
15
Q
what is CN XI
A
accessory or spinal accessory
16
Q
what is CN XII
A
hypoglossal
17
Q
pneumonic for sensory or motor fibers/functions of cranial nerves
A
Some Say Marry Money But My Brother Says Big Brains Matter Most
S = sensory
M= Motor
B = Both
18
Q
function of CN I Olfactory
A
Sensory Only
function = special sensory: smell
19
Q
where do olfactory nerves arise from
A
receptors in the nasal cavity (mucosa)
20
Q
what is the location of the nerve cell bodies of the Olfactory Nerve
A
nerve cell bodies located in the olfactory epithelium (in nasal mucosa)
21
Q
what is Anosmia
A
deficit of olfactory nerve (CN I)
loss of smell
22
Q
the olfactory nerve travels how/through what structures
A
olfactory nerves
through foramina in cribriform plate of ethmoid bone
to olfactory bulb
through olfactory track
to brain
23
Q
what is the function of CN II - optic
A
special sensory: vision
sensory only
24
Q
why is the optic nerve and vision so complex
A
some fibers cross over the optic chiasm, some do not
deficits are complicated; depend on where the trauma is located
25
what is the location of the nerve cell bodies of the optic nerve
retinal ganglia
**exception; doesn't start in brainstem**
26
where in the brain is the optic nerve located
superior to midbrain
27
where in the cranium does the optic nerve travel through
travels through optic canal in the MIDDLE cranial fossa
28
the retina becomes what
optic nerve
29
damage or malfunction of what artery could lead to blindness
ophthalmic artery
30
what are extraocular muscles
eye muscles that attach to the sclera
sclera = white of eye
31
what is the function of the superior rectus muscle
up and in eye movement
32
what is the function of the inferior oblique muscle of the eye
up and out
33
what is the function of the medial rectus of the eye
adduction (to nose)
34
what is the function of the inferior rectus of the eye
moves eye down and in
35
what is the function of the superior oblique muscle of the eye
down and out
36
what is the function of the lateral rectus of the eye
abduction
away from nose
37
what is the equation for the extraocular eye muscles and their corresponding cranial nerve
LR6 SO4 AO3
Lateral rectus = CN VI (abducens)
Superior oblique = CN IV (trochlear)
All other extraocular muscles = CN III (Oculomotor)
38
what is the function of CN III (occulomotor)
Motor function only
innervates 4 extraocular muscles + levator palpebrae superioris
pupil constrictions via parasympathetic innervation of sphincter papillae muscle
lens accommodation for near vision aka focus via parasympathetic innervation of ciliary muscle
39
what is the ciliary muscle
surrounds the lens of the eye
with distant vision it relaxes and flattens
with near vision it contracts and lens becomes more rounded when stimulated by the CN III parasympathetics
40
what are the location of the nerve cell bodies of the oculomotor nerve (CN III) and where can you find it in the brain
bodies found in midbrain
found between midbrain and pons
41
what is ptosis
superior eyelid drooping caused by paralysis of the elevator palpebrae superioris
42
what is lateral strabismus
eye directed down and out
43
what are the deficits of the oculomotor nerve
ptosis
lateral strabismus
absent papillary light reflex
dilated pupil
lack of lens accomodation
44
oculomotor travels through what in the cranium
superior orbital fissure
45
what is the function of CN IV (trochlear)
function = eye muscles superior oblique
*down and out function
46
what is the only CN that exits the posterior surface of the brainstem
trochlear nerve IV
47
what is the location of the nerve cell bodies of CN IV (trochlear) and how can you find in the in the brain
bodies are in posterior midbrain
found laterally between cerebrum and the pons
48
what are 2 common deficits of the trochlear nerve
superior oblique muscle weakness or paralysis
diplopia (double vision) when looking down
49
the trochlear nerve travels through what in the cranium
superior orbital fissure
50
what is the function of the CN V (trigeminal)
sensory AND motor
sensation on forehead, maxilla, mandible
sensation of many parts of face and head (i.e. anterior 2/3 of tongue and part of external acoustic meatus)
motor innervation of mastication muscle + 4 other muscles
51
what are the muscles of mastication
temporalis
masseter
medial pterygoid
lateral pterygoid
52
what is the only muscle of mastication that helps open the mouth
lateral pterygoid
53
what are the branches of sensory function of the trigeminal nerve (CN V)
V1 = ophthalmia nerve (S) (top half of face, forehead, nose)
V2 = Maxillary nerve (S) (lower nose and midface)
V3= Mandibular Nerve (S&M) (Jaw and up through temporal bone)
54
what is the location of the nerve cell bodies of the trigeminal nerve and where can you find it in the brain
nerve cell bodies in trigeminal ganglia and pons
found on the lateral part of the pons
55
what are the common deficits of the trigeminal nerve
weakness/paralysis of mastication muscles
loss of facial sensation
loss of coral reflex (sensation)
56
where in the cranium does the trigeminal nerve cross
V1 = superior orbital fissure
V2=rotundum
V3 = ovale
*standing room only*
57
what is the function of cranial nerve VI (Abducens)
eye muscles: lateral rectus
abducts eye
58
what is the location of the nerve cell bodies of the abducens nerve and how do you find it in the brain
cell bodies in pons
find it between the pons and the medulla
59
deficits of the abducens nerve cause what
loose ability to move eye laterally
medial strabismus: medial muscle acting unopposed
60
Where in the cranium does the abducens nerve travel
abducens pierces the dura covering the clivus then enters the orbit via the superior orbital fissure
61
what are the functions of the CN VII Facial N (x5)
Motor and Sensory
1. muscles of facial expression (+3 muscles)
2. taste sensation to anterior 2/3 Tongue
3. saliva production of sublingual and submandibular glands (para)
4. tear production from lacrimal gland (para)
5. mucous glands of nasal cavity, maxillary sinus, and palate (para)
62
what is the location of the nerve cell bodies for the facial nerve and how can you find it in the brain
bodies located in pons (motor) and geniculate ganglion (sensory)
found lateral to CN 6 between pons and medulla
63
what are the deficits associated with the CN VII (facial N)
loss of corneal reflex (can't blink)
weakened/loss of facial movements
loss of taste from anterior 2/3 of tongue and soft palate
64
the facial nerve travels where on the cranium
through internal acoustic meatus
65
what is the function of the CN VIII (vestibulocochlear)
sensory
special sensory: hearing and balance
66
where are the nerve cell bodies of the vestibulocochlear nerve and how can you find it in the brain
bodies located in vestibular ganglion and spiral ganglion
found lateral to CN 7 at the junction of the pons and medulla
67
what deficits are associated with the vestibulocochlear nerve
tinnitus = ringing or buzzing in ears
vertigo
impaired hearing
68
where does the vestibulocochlear nerve travel through in the cranium
internal acoustic meatus
69
what is the function of the CN IX glossopharyngeal
motor AND sensory
1. swallowing (stylopharyngeus)
2. taste/sensation for posterior 1/3 of tongue
3. sensory from palatine tonsils, oropharynx, middle ear, pharyngotympanic tube, mastoid air cells, carotid body, and sinus
4. saliva production of parotid gland
70
where can you find the nerve cell bodies of the glossopharyngeal nerve and how can you find it in the brain
bodies in medulla (motor) and sensory ganglion (sensory)
found lateral to medulla
71
what deficits are associated with the glossopharyngeal nerve (CN IX)
1. loss of taste and general sensation on posterior 1/3 of tongue
2. changes in swallowing
3. absent gag reflex on ipsilateral side
4. palate deviation on contralateral side
72
where does the glossopharyngeal nerve travel through in the cranium
jugular foramen
73
functions of vagus nerve CN X
motor AND sensory
1. swallowing
2. speech
3. sensory and morot to smooth muscles of thorax/abdomen
4. provides branches to cardiac, esophageal, and pulmonary plexuses
5. viscera of foregut
6. sensory to larynx and laryngopharynx
7. taste from epiglottis and pharynx
8. motor to all muscles of the larynx
9. motor to most muscles of soft palate and pharynx
74
what is the location of the nerve cell bodies of the vagus nerve and how can you find it in the brain
motor bodies found in medulla and nucleus ambiguus in medulla
sensory found in superior and inferior ganglion
in brain arises as a group of rootlets from the lateral surface of the medulla
75
what are some of the common deficits of the vagus nerve
1. dysphagia = difficulty swallowing
2. anesthesia of larynx
3. weak voice/hoarseness
4. dysphonia = difficulty speaking
5. aphonia = loss of voice
6. inspiratory stridor = harsh/high pithces respiratory sound
7. heart rate abnormalities
so much more
76
where does the vagus nerve travel in the cranium
crosses through jugular foramen
77
function of CN XI accessory
motor
sternocleidomastoid and trapezius
78
where are the nerve cell bodies of the accessory nerve located and how can you find the nerve in the brain
cell bodies arise from a series of rootlets from the upper 5-6 segments of the cervical spinal cord
can be found ascending through the foramen magnum lateral to the medulla
79
common deficits of the accessory nerve
atrophy of trapezius and weakened shrugging of shoulders
impaired rotary movements of the neck and chin to the opposite side due to SCM weakness
80
where does the accessory nerve travel in the cranium
enters the foramen magnum
exits the jugular foramen
81
nerve function of the hypoglossal nerve CN XII
major tongue muscles motor innervation
82
where are the nerve cell bodies of the hypoglossal nerve and how can you find it in the brain
cell bodies arise as a series of rootlets from the anterior medulla
found in brain anterolateral to medulla
83
deficits associated with the hypoglossal nerve
when protruded the apex of the tongue deviates toward damaged nerve (ipsilateral side)
84
where in the cranium does the hypoglossal nerve travel
hypoglossal canal
