Anatomy of the PNS Flashcards
(44 cards)
name the 2 types of neuron
multipolar
unipolar
main function of a dendrite
increase surface area of the nervous system
what do schwann cells do?
produce myelin in the PNS not the CNS
what is the main difference between multipolar and unipolar neurons?
multipolar have 2 or more dendrites
where would you find multipolar neruons?
skeletal muscle
ANS
in a multipolar neuron, the cell body will be located in the __ and the axon will be located in the ___
CNS
PNS
where is the cell body of a postsynaptic neuron located?
in a ganglion, not the CNS!
in a unipolar neuron the cell body is located….
the dorsal root ganglion in the PNS not the CNS
what makes up a nerve
groups of axons
how is a mixed modality nerve different from a single modality nerve?
mixed contains different types of nerve in 1 eg somatic motor and sympathetic (think trigeminal)
name the cranial nerves that come off the midbrain
CN III
CN IV
name the cranial nerves that come off the pons
CN V only
name the cranial nerves that come off the medulla
CN IX
CN X
CN XII
spinal nerves are found…
in the intervertebral foraminae ONLY
are the anterior or posterior rami of the spinal nerves larger
anterior are larger
from the horn to the body wall name the different stages of a motor spinal nerve
horn rootlet root spinal nerve ramus (sensory would be this backwards)
there are _ cervical nerves
8
all sensory axons pass from the spinal nerve to the ___ root and eventually into the __ horn of the spinal cord
posterior
posterior
all motor axons follow the ___ route to the body wall
anterior (eg from anterior horn to anterior root etc)
define dermatome
area of skin supplied with sensory innervation from a single spinal nerve
define myotome
the skeletal muscles supplied with motor innervation from a single spinal nerve
the male nipple is at the level of __ dermatome
T4
the umbilicus is at the level of _ dermatome
T10
C2-C4 dermatomes cover what areas?
posterior scalp, neck and shoulder
