PNS Flashcards
afferents
toward brain
efferents
away from brain
somatic sensory (afferent)
skin, bones, muscles, joints
visceral sensory (afferent)
viscera of thoracic and abdominal region > heart, lungs, stomach, urinary bladder
somatic motor (efferent)
skeletal muscle
visceral (automatic) motor
glands, smooth muscle, cardiac muscle
CNS
brain and spinal cord (nucleus-cell bodies) and tracts (axons)
PNS
nerves (axons) and receptors (ganglia-cell bodies)
nerves are protected by three connective tissue coverings
endoneurium (neurolemma)
perineurium
epineurium
neurolemma is made of a
nucleated cytoplasmic layer of the schwann cell
what neurons are the only ones that can repair
the ones with a neurolemma
blindness, speech deficits, tremors, numbness are symptoms of
multiple sclerosis
what degenerates in multiple sclerosis
myelin sheaths and oligodendrocytes in CNS
cervical plexus (C1-C5)
lesser occipital nerve great auricular nerve transverse cervical nerve supraclavicular nerve phrenic nerve suprascapular
schwann cells produce
neurilemma
schwann cells make oligodendrocytes make the myelin sheath in different directions (true or false)
true
gaps in myelin sheaths
nodes of ranvier
segments covered by myelin sheaths are called
internodes
