Skeletal Muscle Contraction: Step-by-Step Sequence Explained

1. An action potential reaches the synaptic terminal of the motor neuron.

2. Neurotransmitter is released from the synaptic terminal.

3. Neurotransmitter binds to receptors on the motor end plate.

4. An action potential is generated in the muscle fiber.

5. The action potential travels along the T-tubules.

6. Calcium ions are released from the sarcoplasmic reticulum.

7. Calcium ions bind to troponin, causing a conformational change.

8. Tropomyosin moves, exposing the myosin-binding sites on actin.

9. Myosin heads bind to actin, forming crossbridges.

10. Myosin heads hydrolyze ATP, causing a power stroke.

11. The crossbridges detach from actin.

12. The muscle fiber relaxes.