muscle contraction step 3

excitation of muscle fiber

step 1

arrival of nerve signal, nerve is activated, calcium enters axon terminal via voltage gated channels

step 2

ACh is released via exocytosis of synaptic vesicles

step 3

ACh binds to receptor

step 4

opening of ligand-regulated ion gate; creation of end-plate potential (EPP)

step 5

epp causes opening of voltage-regulated ion gates; creation of action potentials

action potentials (AP)

voltage change that spreads across entire membrane, muscle = excited

resting cell voltage

-90 mV

cell voltage after Na+ flows in

30 mV