nervous Flashcards
central nervous system
brain and spinal cord
peripheral nervous system
all nerves that branch off from brain and spine
-sends signals both directions
afferent
picks up sensory stimuli
efferent
motor- sends directions from brain to muscles and glands
motor/efferent divisions
- somatic- voluntary
2. autonomic-involuntary
autonomic divisions
- sympathetic- mobilizes action
2. parasympathetic- relaxes
glial cell types
- astocytes- blood support
- microglial- immunity protect
- ependymal cells- line cavaties/ spinal fluid
- oligodendrocytes- wrap and insulate (myelin sheath)
peripheral NS glial cell types
- satellite cells-surround neuron cell bodies
2. schwann cells- insulate (myelin sheath)
sensory neurons
afferent, transmit impulses from sensory receptors to CNS, mostly unipolar
motor neurons
efferent, impulse moves from CNS to rest of body, mostly multipolar
interneurons
association neurons in CNS, most abundant, impulse moves between sensory and motor, multipolar
resting membrane potential
-70
charge needed for action potential
-55
depolarization charge
+40
saltatory conduction
leaping with myelin sheath