Chapter 14- Peripheral Nervous System Flashcards
Peripheral Nervous system made of?
Mixed nerves (contain afferent and efferent axons)- all spinal nerves are mixed nerves Motor nerves (only efferent axons) Sensory nerves (only afferent axons)
How many pairs of cranial nerves are there?
12
Cranial nerves are…
Attached to the brain and pass through the skull foramina; numbered with roman numerals from rostral to caudal; each nerve is either motor, sensory or mixed
Identify all 12 cranial nerves from top view of brain
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CN I: Olfactory
Composed of very short fibers; sensory; doesn’t form tight nerve; bipolar neurons that are olfactory neurons; olfactory bulb is not cranial nerve I it is where olfactory nerve synapses
CN II: Optic
Axons of the retina converge to form the optic nerve; passes through the optic foramen into the brain; from eye to chiasma; sensory- vision
CN III: oculomotor
Motor- moves the eyeball and eyelid; parasympathetic; activates skeletal muscles that move eyeball
Palpebrae=
eyelid
CN IV: trochlear
Motor- moves the eyeball; smallest CN; only cn from DORSAL brainstem; innervates the superior oblique muscle and that’s all
CN V: trigeminal
MIXED
- Motor: muscles of mastication (chewing only)
- Sensory: All facial sensations
CN VI: Abducens
Motor- moves the eyeball
runs along the middle of pons; activates lateral rectus muscles (ABDUCTS the eyeball)
CN VII: facial
MIXED
- Motor: Facial expression
- Sensory: taste in anterior 2/3rds of tongue
NOT FOR CHEWING
CN VIII: Vestibulocochlear
Sensory- equilibrium and audition
CN IX: Glossopharyngeal
MIXED
- Sensory: taste for the posterior 1/3 of the tongue
- Motor: swallowing muscles
CN X: Vagus
BIGGEST CN Nerve; only one that goes past the neck (fibers innervate most organs of ventral body cavity); MIXED
- Sensory: visceral sensation and taste from throat region
- Motor: supplies muscles of the pharynx, larynx and soft palate that are involved in swallowing and vocalization