Cranial Nerves

Question 1

CN I

Answer 1

olfactory nerve SVA for sense of smell

special visceral afferent

Question 2

CN I pathway

Answer 2

leaves nasal cavity (nerve) > enters vault thru cribiform plate (bulb) > limbic lobe of cerebral cortex (tract)

Question 3

CN II

Answer 3

optic nerve SSA

ability to see

special somatic afferent

Question 4

CN II pathway

Answer 4

1. receptors (rods and cones)
2. leave eye from retina
3. form optic nerve
4. enter anterior cranial fossa thru optic canal
5. specific retinal fibers cross at chiasm
6. tract leads fibers to thalamus
7. radiations lead to cortex around calcarine fissue @ occipital lobe

Question 5

CN III

Answer 5

oculomotor nerve - GSE and GVE

ability to move and blink eyes
pupil constriction

general somatic/visceral efferent

Question 6

CN III pathway

Answer 6

midbrain interpeduncular foss > SOF > orbit

synapses at ciliary ganglion (pre)

Question 7

CN III GVE innervates

Answer 7

parasymps to ciliary ganglion, ciliary muscle, sphincter pupillae

Question 8

CN III GSE muscles

Answer 8

motor to extraoculaur muscles (skeletal)
-levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, inferior oblique

Question 9

CN IV

Answer 9

trochlear nerve GSE

ability to move eyes up/down/back/forth via superior oblique muscle

Question 10

CN IV pathway

Answer 10

from midbrain posteriorly inferior to colliculi > leaves middle fossa thru SOF

Question 11

CN V

Answer 11

trigeminal nerve GSA and SVE

sensations in face and cheeks, taste
jaw movement

general somatic afferent, special visceral efferent

Question 12

CN V GSA

Answer 12

sensory to face, orbit, nasal, oral cavity
trigeminal ganglion

Question 13

CN V SVE

Answer 13

motor to muscles of mastication- mylohyoid, ant belly digastric, tensory tympani, tensor veli palatini

mandibular branch (v3) only one that does motor, v1 and v2 sensory only

pharyngeal arch

Question 14

CN VI

Answer 14

abducens nerve GSE

ability to move eyes via lateral rectus muscle ‘abducts the eye’

Question 15

CN VI pathway

Answer 15

near midline at pontmedullary junction > middle fossa thru SOF
-nucleus is in pons

Question 16

CN VII

Answer 16

facial nerve

facial expressions
sense of taste

Question 17

CN VII SVE

Answer 17

motor to muscles facial expression
-stylohyoid
post belly digastric
stapedius in ear

Question 18

CN VII GVE

Answer 18

parasymp motor
-synapses @ pterygopalatine (deep face) and submandibular ganglia

-lacrimal, nasal, palatine glands
-submandiublar and sublingual glands

Question 19

CN VII GSA

Answer 19

sensory to external auditory meatus (ear canal)

Question 20

CN VII GVA

Answer 20

pressure and chemistry from nasal cavity, soft palate, adj pharyngeal wall

Question 21

CN VII SVA

Answer 21

taste to anterior 2/3 tongue

Question 22

CN VII pathway

Answer 22

1. pons at lateral pontomedullary junction
2. internal auditory meatus
3. facial canal
4. stylomastoid foramen
5. branches to glands and muscles

Question 23

CN VIII

Answer 23

cochlear/vestibular nerve SSA

sense hearing and balance

Question 24

CN VIII pathway

Answer 24

from pons > enters internal auditory meatus to internal ear (petrous portion)

Question 25

CN IX

Answer 25

glossopharyngeal nerve ability to taste and swallow

Question 26

CN IX SVE

Answer 26

motor to pharyngeal constrictors and stylopharyngeus pharyngeal arch 3

Question 27

CN IX GVE

Answer 27

parasymp motor to parotid gland -synapses at otic ganglion

Question 28

CN IX GSA

Answer 28

general sense to post 1/3 of tongue

Question 29

CN IX SVA

Answer 29

taste to posterior 1/3 tongue

Question 30

CN IX GVA

Answer 30

carotid sinus -special pathway: leaves medulla posterior to olive > enters jugular foramen to leave post fossa

Question 31

CN X

Answer 31

vagus nerve digestion and heart rate

Question 32

CN X SVE

Answer 32

motor to muscles of larynx pharyngela arch 4

Question 33

CN X GVE

Answer 33

parasymp to thoracic and abdom viscera thru left colic flexure of large intestine -synapse at gangllia within walls of organ

Question 34

CN X GSA

Answer 34

sensory to external auditory meatus

Question 35

CN X GVA

Answer 35

aorta and gut baro/chemoreceptors

Question 36

CN X SVA

Answer 36

taste to epiglottic region

Question 37

CN X pathway

Answer 37

medulla behind olive > leave thru jug foramen

Question 38

CN XI

Answer 38

accessory nerve GSE shoulder and neck muscle movement via motor to SCM and trap

Question 39

CN XI pathway

Answer 39

upper cervical spinal cord > ascends thru foramen magnum > joins IX and X thru jugular foramen

Question 40

CN XII

Answer 40

hypoglossal nerve GSE ability to move your tongue via all intrinsic and extrinsic muscles of tongue

Question 41

CN XII pathway

Answer 41

medulla anterior to olive > leaves thru hypoglossal canal