3.7 PNS stuff 2 Flashcards
“unmyelinated”
shares myelin with other cells
each PNS axon is myelinated and coated with
endoneurium
fascicle
bundle of axons coated with perineurium
epineurium
coats bundle of fascicles (nerve)
mesoneurium
- coats the epineurium
- connective tissue that protects the fascicles
perineurium
- continuous with arachnoid mater
- forms the blood nerve barrier
blood nerve barrier
protective mechanism to keep toxins from getting into the nerves
ramus
division/offshoot of a spinal nerve
ventral rami innervate
lateral anterior regions
dorsal rami innervate
paravertebral (midline posterior) and intercostals
in a PNS nerve bundle, there what signals are happening?
afferents AND efferents
peripheral nerves (signals)
- peripheral nerve ⟺ viscera (autonomic)
- peripheral nerve ⟺ somatic » motor
sensory » somatic
sensory » cutaneous
cutaneous » sweat glands, arterioles, sympathetic efferents
muscular
can be either muscular or can get proprioceptive input
What are the plexuses?
- cervical
- brachial
- lumbar
- sacral