Head and Neck Cranial Nerves pt 1

Question 1

What is CN I and what is the function

Answer 1

Olfactory nerve
Olfaction

Question 2

What is CNII and what the function?

Answer 2

optic nerve
vision

Question 3

what is CN III and what is the function?

Answer 3

oculomotor nerve
eye movements, pupil constriction

Question 4

what is CN IV and what is the function?

Answer 4

trochlear nerve
eye movements

Question 5

what is CN V and what is the function?

Answer 5

trigeminal nerve
facial sensation, muscles of mastication

Question 6

what is CN VI and what is the function?

Answer 6

abducens nerve
eye movements

Question 7

what is CN VII and what is the function?

Answer 7

facial nerve
muscles of facial expression, taste, lacrimation, salivation

Question 8

what is CN VIII and what is the function?

Answer 8

vestibulocochlear nerve
hearing, equilibrium sense

Question 9

what is CN IX and what is the function?

Answer 9

glossopharyngeal nerve
pharyngeal muscles, carotid body reflexes, salivation

Question 10

what is CN X and what is the function?

Answer 10

vagus nerve
parasympathetics to most organs, laryngeal muscles (voice), pharyngeal muscles, aortic arch reflexes

Question 11

what is CN XI and what is the function?

Answer 11

spinal accessory nerve
head turning (trapezius and sternomastoid)

Question 12

what is CN XII and what is the function

Answer 12

hypoglossal nerve
tongue movement

Question 13

What CN is responsible for facial sensation

Answer 13

CN V

Question 14

what CN is responsible for sensory in the ear canal?

Answer 14

CN VII, IX, X

Question 15

what CN is responsible for sensory in the pharynx?

Answer 15

CN IX

Question 16

what CN is responsible for smell?

Answer 16

CN I

Question 17

what CN is responsible for vision

Answer 17

CN II

Question 18

what CN is responsible for hearing and balance?

Answer 18

CN VIII

Question 19

What CN is responsible for taste?

Answer 19

CN VII, IX, X

Question 20

How does the olfactory nerve elicit smell?

Answer 20

Olfactory bulb sends out olfactory nerves that reaches into the superior nasal cavity

Question 21

How does the optic nerve elicit sight?

Answer 21

1) Retina sends out axons through left and right optic nerve
2) The axons switch at optic chiasm
3) Axons synapse in the lateral geniculate nucleus
4) then travels to occipital lobe

Question 22

what are the rods responsible for?

Answer 22

b/w, movement

Question 23

what are cones responsible for?

Answer 23

color, details

Question 24

What is created when light enters the eye? what do the parts of the visual field project?

Answer 24

reversed image
Upper visual field projects to the inferior retina, lower visual field projects to the superior retina

Question 25

What happens if theres an impingement of an optic nerve?

Answer 25

visual deficits affecting one eye

Question 26

what happens if theres an impingement of optic radiations?

Answer 26

homonymous hemianopia - one visual field

Question 27

what happens if there is an impingement of the optic chiasm?

Answer 27

bitemporal hemianopia: loss of signals from each nasal retina --> loss of each temporal field

Question 28

What happens if theres an impingement of a single optic radiation (in Meyer's loop)?

Answer 28

quadrantanopia - loss of visual field quadrant

Question 29

What happens if theres a lesion of the oculomotor nerve?

Answer 29

Leaves only lateral retus and superior oblique intact "down and out" appearance

Question 30

what happens if theres a lesion of the trochlear nerve

Answer 30

-Damaged superior oblique -Reported double vision when looking in and down with affected eye, when going down stairs -Head tilt away from affected side

Question 31

What happens if theres a lesion of the abducens nerve

Answer 31

lateral rectus damage inability to look laterally past midline reported double vision when looking laterally often due to internal carotid aneurysm

Question 32

What is an early sign of increased intracranial pressure? What is the cause?

Answer 32

Loss of parasympathetic effect of an eye (always dilated) Dura mater pushing against oculomotor nerve

Question 33

What is the most common aneurysm to cause CN III compression?

Answer 33

posterior communicating artery

Question 34

What is the parasympathetic effect on lens when ciliary muscle is relaxed?

Answer 34

Relaxation of muscle = stronger/tenser fibers = flat lens

Question 35

What are the CN responsible for motor to somite-derived muscles?

Answer 35

CN III, IV, VI - eyes CN XI - SCM, trapezius CN XII - tongue

Question 36

What CN are responsible for motor to muscles of pharyngeal arches?

Answer 36

CN V - muscles of mastication CN VII - Facial muscles CN IX - pharynx CN X - palate, pharynx, larynx