1. A nerve impulse reaches the end of the axon (axon terminal) 2. Calcium channels in the axon membrane open, allowing CA2+ to flow into the axon terminal 3. Presence of CA2+ causes some of the synaptic vesicles to fuse to the axonal membrane and release ACh into the synaptic cleft 4. ACh diffuses across the cleft and attaches to ACh receptors on the sarcolemma 5. Sarcolemma becomes permeable to Na+ 6. Na+ rushing into the cell generates an action potential 7. Once started, muscle contraction cannot be stopped (cross-bridge cycle) 8. Acetylcholinesterase (AChE) recycles now-released ACh back into the axon terminal

1. A nerve impulse reaches the end of the axon (axon terminal) 2. Calcium channels in the axon membrane open, allowing CA2+ to flow into the axon terminal 3. Presence of CA2+ causes some of the synaptic vesicles to fuse to the axonal membrane and release ACh into the synaptic cleft 4. ACh diffuses across the cleft and attaches to ACh receptors on the sarcolemma 5. Sarcolemma becomes permeable to Na+ 6. Na+ rushing into the cell generates an action potential 7. Once started, muscle contraction cannot be stopped (cross-bridge cycle) 8. Acetylcholinesterase (AChE) recycles now-released ACh back into the axon terminal