Nerve impulses reaches end of axon.

Calcium channels in the axon membrane open allowing calcium ions to flow into axon terminal.

Presence of calcium ions causes some of the synaptic vesicles to fuse to the axonal membrane and release ACh into the synaptic cleft via exocytosis.

Acetylcholine diffuses across the cleft and attaches to Acetylcholine receptors on the sarcolemma

Sarcolemma becomes permeable to Na+.

Na+ rushing into cell generates action potential.

Once started, muscle contraction cannot be stopped.

Acetylcholinesterase recycles now released Acetylcholine back into Axon terminal.

Nerve impulses reaches end of axon. Calcium channels in the axon membrane open allowing calcium ions to flow into axon terminal. Presence of calcium ions causes some of the synaptic vesicles to fuse to the axonal membrane and release ACh into the synaptic cleft via exocytosis. Acetylcholine diffuses across the cleft and attaches to Acetylcholine receptors on the sarcolemma. Sarcolemma becomes permeable to Na+. Na+ rushing into cell generates action potential. Once started, muscle contraction cannot be stopped. Acetylcholinesterase recycles now released Acetylcholine back into Axon terminal.