Cranial Nerves Flashcards
Nerve
A bundle of axons in the PNS - so nerves are only in the PNS
Some nerves meet up with the brain and they are called…
cranial nerves
Some nerves meet up with the spinal cord and they are called…
spinal nerves
Cranial nerves always come in…
pairs
There are ___ pairs of cranial nerves
12
Some pairs of cranial nerves consist of ______ or. _____ neurons only and some pairs are ____
SENSORY OR MOTOR;
some pairs are MIXED - they convey both sensory and motor info
p 83 coloring book
The olfactory nerve
Cranial nerve I - entirely sensory
Neurons in the upper nasal cavity respond to odor stimuli and convey impulses to olfactory bulbs and tracts which lead to the primary olfactory area in the temporal lobe of the cerebral cortex.
The optic nerve
Cranial Nerve II - entirely sensory
Rods and cones in the retina receive visual stimuli, relay them to bipolar neurons and then to ganglion cells. Axons of ganglion cells from each eye form the optic nerves.
The primary visual area is in the occipital lobe of the cerebral cortex.
Oculomotor, trochlear, and abducens nerves
Oculomotor- cranial nerve III
trochlear - cranial nerve IV
abducens - cranial nerve VI
only motor nerves
The oculomotor and trochlear nerves arise from the midbrain while the abducens nerve starts in the pons.
Trigeminal nerve
cranial nerve V
MIXED cranial nerve
It conveys sensory information related to touch, pain and thermal sensations from three regions of the face to the brain stem.
The motor portion primarily controls muscles of mastication (chewing).
Facial Nerve
cranial nerve VII
MIXED cranial nerve
The sensory portion of this nerve leads from receptors in taste buds and from receptors for touch, pain, and thermal stimuli from the skin of the ear canal.
The motor portion leads to muscles of the face, scalp, and neck as well as to glands for salivation, tears and nasal secretions.
Vestibulocochlear nerve
Cranial nerve VIII
SENSORY nerve - with two branches (vestibular and cochlear) leading to the brain from the inner ear
previously called acoustic or auditory nerve
The vestibular branch conveys sensory information for equilibrium while the cochlear branch relays sensory impulses for hearing.
Glossopharyngeal nerve
cranial nerve IX
MIXED cranial nerve
It caries a wide variety of sensory information for taste, swallowing, blood pressure, blood gas levels, and the external ear (touch, pain and temperature).
The motor portion conveys impulses to muscles for swallowing and some of the salivary glands.
Vagus nerve
CN X
MIXED nerve
It conveys sensory and motor impulses to many of the thoracic and abdominal organs among many other functions.
If interested, your texts specify other functions.
Accessory nerve
CN XI
MOTOR nerve
It conveys motor impulses to the sternocleidomastoid and trapezius muscles and is therefore a key nerve involved in coordinating movements of the head and neck.
