# data[].attributes.body
step four : the cocking of the myosin head where ATP is hydrolyzed to ADP and p1 and the myosin head returns to its high energy position

# data[].attributes.body
step three : the cross bridge detachment after the ATP attaches to the myosin, the link now weakens and detaches.

# data[].attributes.body
step two : the working stroke where ADP and p1 are released and the myosin head pivots and bends (now in low energy position), pulling the actin filament towards the m line.

# data[].attributes.body
step one : the cross bridge formation where the myosin head attaches to the actin myofilament.

# data[].attributes.body
step three : Ca2+ combines with troponin and removes the blocking action of the tropomyosin by changing the shape of the actin so the myosin binding sites are exposed.

# data[].attributes.body
step two : the transmission of action potential along the t tubules causes adjacent sarcoplasmic reticulum to release Ca2+ which flows into the cytoplas

# data[].attributes.body
step one : the action potential moves down the sarcolemma and down the t tubules.

# data[].attributes.body
the brain sends a nerve impulse (action potential) through the motor unit to a neuromuscular junction. the action potential cause voltage gated Ca+ channels to open allowing Ca+ to enter. this stimulates the release of Ach which releases into the cleft. Ach binds to Ach receptors and activates voltage gated Na+ channels which pump Na+ in and K+ out causing the cell interior to be depolarized. This depolarization spreads, opening more Na+ channels for the action potential to travel down the sarcolemma. Na+ concentrations from this cause change in membrane permeability, opening K+ channels to allow K+ to enter and diffuse across membrane (repolarization).