lecture 26 - resting membrane potentials - PoNF

action potential

transmit signals over LONG distance

graded potential

decide when an action potential should be fired (axon hillock)

resting membrane potential

the electrical charge of a neuron when it is not active

resting membrane potential value

-70 mV

describe the ionic basis of resting membrane potential

inside negative charge relative to outside

sometimes called potential difference

- K+ ions cause this

how is a resting membrane potential generated

Na/K pump - uses ATP to pump K+ into cell

- imbalance of charges

add leaky K+ channel

- builds up electrical gradient

- equilibrium is reached when electrical gradient is equal and opposite to concentration gradient

small concentration gradient

small resting membrane potential

large concentration gradient

needs a lot of K+ to leak out to reach equilibrium

main cause of resting membrane potential

leaky K+ channels in membrane