action potential

what is resting membrane potential?

difference in charge between inside and outside of a cell

do all cells have a resting membrane potential?

yes

do all cells manipulate their resting membrane potential?

no, only nerve and muscle

where is there more sodium?

interstitial fluid, extracellular

where is there more potassium?

cytosol, intracellular

what kind of transport is the Na/K pump?

active

how many Na and K are moved by the pump?

3 Na and 2 K

in resting membrane potential, where is the charge higher?

outside

when is the cell membrane polarized?

resting

what is the limiting factor in an action potential?

depolarization to threshold

what is the trigger to depolarizaiton?

voltage gated Na channels open

what happens to the charge when Na ions rush into the cell?

membrane potential becomes positive

is depolarization all or nothing?

yes

what happens during repolarization?

Na channels close and K channels open

what happens when the gated K channels close again?

membrane potential briefly hyperpolarizes to -90

where do channels open?

nodes of ranvier only

what is the charge of Na?

+

what is the charge of K?

+

what is the site of transmission of action potential from one cell to another?

synapse

what is the gap that separates presynaptic axon and postsynaptic cell m,embrane?

synaptic cleft

what does an incoming nerve impulse trigger?

release of a neurotransmitter

where do neurotransmitters bind?

cell surface receptors on postsynaptic cell membrane

what does the influx of Ca trigger?

exocytosis of neurotransmitters