lecture 4: neurons and membrane potential Flashcards
astrocytes
support cells, control extracellular environment of neurons
microglia
“immune system” of the CNS
ependymal cells
ciliated involved with production of CSF and CSF movment
oligodendrocytes
responsible for myelinatino
sensory neurons
afferent neurons of PNS (go to brain)
motor neurons
efferent (away from brain)
What does SAME stand for
sensory afferent, motor efferent
interneurons
communication within CNS and between sensory/motor
neural plasticirty
early in development, the brain has much greater potential for remodeling in response to stimulation or injury than in the adult brain
what is the resting membrane potential
-70 mV
depolarization is movement closer to
0 mV
membrane potential exists because of
concentration gradients intracellular-extracellular
selective permeability of membrane
sodium-potassium ATPase
selective permeability of leak channels, along with the action of the sodium-potassium ATPase, lead to the development of
membrane potential
graded potential
- change in membrane potential affecting a local area
- signal decreases as distance from stimulus increases
when the cell is repolarizing, Na+ channels are in the __ state
inactivated
which two channels often serve as the initial stimulus for an action potential
ligand-gated and mechanically gated
voltage-gated Na+ channels __ the cell
depolarize
voltage-gated K+ channels __ the cell
repolarize
absolute refractory period
cell is incapable of depolarizing
relative refractory period
cell can depolarize if supplied with a stronger-than-usual stimulus
action potential propagation
build of action potentials
* the velocity with which an action potential propagates along a membrane depends upon fiber diameter and whether or not the fiber is myelinated
what is the most optimal fiber for an AP to travel down
larger diameter, myelinated
saltatory conduction
when an AP jumps from node to node
