Cranial Nerves

Question 1

Cranial Nerves

Answer 1

12 pairs of nerves associated with the brain. Roman numerals I through XII

Question 2

Olfactory I

Answer 2

Sensory-olfaction (smell)-passes through ethmoid bone.

Question 3

Optic nerve II

Answer 3

Vision-sensory- arises from retina and partially crosses over at optic chia am.

Question 4

Oculomotor nerve III

Answer 4

Innervates 4 of 6 extrinsic muscles of the eye ball. Iris, eyelid, and muscle that alters the lens. Moves the eyeball, raises the eyelid, pupil constriction, lens accommodation. Motor only.

Question 5

Trochlear nerve IV

Answer 5

Innervates 1-6 extrinsic muscles of the eyeball. Eyeball movement motor only.

Question 6

Trigeminal Nerve V

Answer 6

Largest cranial nerve, three divisions, V1, V2, V3. Functions all facial sensation, chewing, mixed both motor and sensory.

Question 7

Abducens VI

Answer 7

Innervates 1of 6 extrinsic muscle of the eyeball. Function eyeball movement-motor only

Question 8

Facial VII

Answer 8

Chief motor nerve that has five branches: temporal, zygomatic, mandibular, Buffalo, cervical. Functions: produce all facial movement, taste, tear production, saliva production, mucus production in nose and mouth. Motor and sensory.

Question 9

VIII Vestibulocochlear Nerve

Answer 9

Cochleae division (hearing) merges with vestibule division (equilibrium) functions: equilibrium, audition (hearing) mostly sensory

Question 10

IX Glossopharyngeal Nerve

Answer 10

Innervates pharynx and part of the tongue. Functions: swallowing saliva production, taste, general pharyngeal sensations. Mixed-both motor and sensory.

Question 11

X Vagus Nerve

Answer 11

Only cranial nerve that extends beyond head and neck, major nerve of the parasympathetic nervous system (“rest and digest”) helps regulate the activity of the heart, lungs, abdominal viscera. Transmits sensory information about blood pressure, blood chemistry, taste, and viscera. Functions: taste, general sensory info about (deep pain/distortion) chemoreceptors sense co2 and o2 in blood aorta. Baroreceptors sense blood pressure in aorta. Lowers breathing rate. Causes bronchoconstriction.

Question 12

XI Accessory Nerve

Answer 12

Supplies two large neck muscles. Primarily motor functions. Functions:shrugging shoulders, via the trapezius, turning of head.

Question 13

XII Hypoglossal Nerve

Answer 13

Innervates the intrinsic and extrinsic muscles of the tongue. Functions: tongue movement, motor only, contributes to swallowing, manipulating food during chewing, and speech production.