Ch 5 (test 1) Flashcards
The difference between in charge b/w the inside of the cell and the outside of the cell
membrane potential
Negative membrane potential
charge on inside less than outside
Positive membrane potential
charge on inside is more than outside
Diffusion potentials are set up by what type of transport (Na/K pump)
active transport
Resting membrane potential of periphery
-90 mV
resting membrane potential of CNS
-65 mV
Na/K pump sends how many Na and K which way thru the cell
3 Na out of cell
2 K inside cell
Na/K pump has what 2 purposes in regard to the resting membrane potential
1) sets up neg. resting membrane potential
2) creates concentration gradients (diffusion potentials)
Rapid change in the membrane potential that spreads rapidly along the nerve fiber membrane
action potential
Depolarization–Ascending or descending
ascending
repolarization–ascending or descending
descending
Na and K, enter or leave the cell during the depolarization or repolarization stage
Na enters during depolarization
K enters during repolarization
Na and K move in and out of the cell during an action potential via what
diffusion via voltage gated channel
what stage is known as recharging the membrane
Post action potential
what causes a plateau in action potentials
Ca channels open, calcium enters. And the very slow opening of voltage gated K channels
what is the purpose of hyperpolarization
inhibits next AP from occuring too soon
rhythmicity of tissues occurs due to what
b/c of leaky Na/Ca channels that leak into the cell
AP jumps from ____ to ____
node to node
local anesthetics inhibit what
voltage gated Na channels, thus depolarization doesnt occur
tetany
severe tonic contractions due to abnormal Ca metabolism
spontaneous depolarization
decreased Ca ions in the ECF results in a more positive resting membrane potential
