What are the steps of skeletal muscle contraction?

Skeletal muscle contraction occurs over a series of steps that involve repetitive stretching and relaxing of the muscle fibers. The Sliding Filament Theory is the most-widely accepted theory that describes the process. According to this theory, these are the general steps of skeletal muscle contraction: 

1. The brain or spinal cord sends a nerve impulse to the muscle tissue through neurons. 
2. When the nerve impulse reaches the neuromuscular junction of a myocyte, Calcium (Ca++) ions are released on the junction, triggering the release of the neurotransmitter, Acetylcholine. 
3. An action potential is generated when the released Acetylcholine binds to the receptor on the sarcolemma of the myocyte. The action potential allows Sodium (Na+) ions to flow and diffuse into a muscle fiber. This causes depolarization and generates a wave of action potential across sarcolemma, which triggers the release of Ca++ ions from the sarcoplasmic reticulum. 
4. The Ca++ ions that are released bind with the troponin protein in the actin filament, eliminating the protein tropomyosin from the actin binding site. 
5. A cross-bridge is formed when a myosin head binds with an actin filament, and pulls it inward, causing the actin filament to slide along myosin. This shortens the sarcomere, which results in contraction in the muscle fiber. 
6. At the same time of the myosin-actin cross-bridge formation, ATP binds to the myosin and hydrolyzes to ADP, which releases energy in the form of a phosphate molecule. This sends the myosin head to a low-energy state, causing it to detach from the actin filament and break the cross-bridge. 
7. With the cross-bridge broken, the sarcomere returns to its original length and the muscle relaxes.
8. The myosin releases ADP, which binds with the free phosphate molecule, forming ATP, which provides energy for another muscle contraction.