cranial nerves

Question 1

what are the 12 cranial nerves?

Answer 1

I olfactory
II optic
III oculomotor
IV trochlear
V trigeminal
VI abducens
VII facial
VIII vestibulocochlear
IX glossopharyngeal
X vagus
XI spinal accessory
XII hypoglossal

Question 2

what are the 3 main functional components of CN?

Answer 2

1. motor to voluntary muscles
   - somatic motor
   - brachial motor
2. motor to involuntary muscles
3. sensory
   - from viscera
   - general sensation
   - special senses

Question 3

describe CNI olfactory

Answer 3

special sensory
p;factory epithelium
smell from nasal mucosa of each nasal cavity, nasal septum and superior conchae
test: minty smell

Question 4

describe CNII optic

Answer 4

special sensory
nerve cell bodies in retina
exits orbital canal(optic chiasm)
vision from retina

Question 5

describe CNIII oculomotor

Answer 5

somatic motor-midbrain
-superior rectus 
-medial rectus 
-inferior oblique
-levator palpebrae
-superioris
visceral motor
-P/S to sphincter pupillae & ciliary muscle
via ciliary ganglion

Question 6

describe CNIV trochlear

Answer 6

somatic motor
cell bodies in midbrain
motor to superior oblique
-turns eye down & out

Question 7

describe trigeminal CNV1 ophthalmic

Answer 7

general sensory
sensation from:
cornea, skin of forehead, scalp, eyelids, nose, mucosa of nasal cavities & paranasal sinuses

Question 8

describe CNV2 maxillary

Answer 8

general sensory
sensation from:
face over maxilla
upper lip
maxillary teeth
maxillary sinuses

Question 9

describe CNV3 mandibular

Answer 9

general sensory
sensation from:
side of mandible
mandibular teeth
mucosa of mouth and anterior 2/3 of tongue

Question 10

describe CNVI abducents

Answer 10

somatic motor
arises from pons
motor to lateral rectus
eye muscles
test: follow fingers H shape

Question 11

describe CNVII facial

Answer 11

bracial motor:
-motor to muscles of facial expression, scalp, stapedius
special sensory:
taste to ant. 2/3 tongue and palate
visceral motor:
P/S to submandibular and sublingual
salivary glands, lacrimal gland & glands of nose & palate

Question 12

describe CNVIII vestibulocochlear

Answer 12

special sensory
vestibular sensation
hearing from spiral organ

Question 13

describe CNIX glossopharyngeal

Answer 13

somatic motor:
-motor to stylopharyngeus
visceral motor:
-P/S to parotid
visceral sensory:
-parotid, pharynx, middle ear
special sensory:
-posterior 1/3 tongue
somatic sensory:
-external ear

Question 14

describe CNX vagus

Answer 14

somatic motor:
-muscles of pharynx
-intrinsic muscles of larynx
-muscles of palate
-muscle in upper 2/3 oesophagus
visceral motor:
-P/S to trachea, bronchi, GIT, heart
visceral sensory:
-tongue, larynx, resp. tract, heart, upper GI to left colic flexure
special sensory:
-epiglottis & palate
general sensory:
-auricle, external auditory meatus

Question 15

describe CNXI spinal accessory

Answer 15

somatic motor
sternocleidomastoid
trapezius

Question 16

describe CNXII hypoglossal

Answer 16

somatic motor

motor to intrinsic and extrinsic muscles of tongue