how many pairs of cranial nerves are there?
12 pairs
what structures do they serve?
head and neck with the exception of the vagus nerve that extends into the abdomen
what is the first cranial nerve and its function?
I Olfactory
afferent impulses for sense of smell
what is the second cranial nerve and its function?
ll Optic
afferent impulses for vision
what is the third cranial nerve and its function
lll Oculomotor
-somatic motor fibers that direct eyeball and raise upper eyelid
-autonomic motor nerve fibers for pupil constriction and visual focusing
-proprioceptor afferents
what is the fourth cranial nerve and its function?
IV Trochlear
-primarily motor nerves
-supplies somatic nerve fibers to superior oblique muscle of extrinsic eye
what is the fifth cranial nerve and its function?
V Trigeminal
-general sensation
what is the sixth cranial nerve and its function?
VI abducens
-supplies somatic motor fibers to lateral rectus muscle, an extrinsic muscle of the eye
what is the seventh cranial nerve and its function?
VII facial
-mixed nerves
-motor impulses to skeletal muscles of face for facial expressions
-transmits parasympathetic motor impulses to glands
-taste
what is the eighth cranial nerve and its function?
VIII vestibulocochlear
-sensory, hearing
-afferent impulses for equilibrium and balance
what is the ninth cranial nerve and its function?
IX glossopharyngeal
-mixed nerves that innervate tongue and pharynx
-parasympathetic motor nerve fibers for salivary glands
-sensory fibers for taste
what is the tenth cranial nerve and its function?
X vagus
-mixed nerves
-parasympathetic motor fibers supply heart, lungs, and abdominal viscera
-involved in regulating heart beat, breathing, and digestive system activtiy
-motor fibers for pharynx and larynx
-sensory fibers, taste
what is the eleventh cranial nerve and its function?
XI accessory
-mixed nerves
-primarily motor in function
-supply motor fibers to trapezius and sternocleidomastoid muscles
-proprioceptor impulses from same muscles
what is the twelfth cranial nerve and its function?
XII hypoglossal
-mixed nerves
-somatic motor fibers and proprioceptor fibers to muscles of tongue
-tongue movements to manipulate food during chewing
-swallowing and speech