# data[].attributes.body
step 2: The power stroke

# data[].attributes.body
Step 3: Cross bridge detachment

# data[].attributes.body
Step 4: Cocking of the myosin head.

# data[].attributes.body
step 1: Cross bridge formation

# data[].attributes.body
Step 3 and 4: Ca2+ combines with troponin and removes the blocking actin of tropomyosin by changing the shape of the actin so that the myosin binding site are expose. This binding forms a cross bridge and starts contraction.

# data[].attributes.body
Step 2: Transmission of the action potential along the T tubules cause the adjacent sarcoplamic reticulum (SR) to release Ca2+ which flows into cytosol

# data[].attributes.body
Step 1: The action potential moves down the sarcolemma and down the T tubules

# data[].attributes.body
The brain sends a action potential down to a neuromuscular junction which causes the voltage gated calcium ion channels to open thus allowing calcium to enter the neuron. This release of calcium stimulates the release of ACh which binds to a ACh receptor sight and activates  voltage-gated Na+ ion channels. When Na+ is pumped in and K+ out, Na+ is pumped in more causing interior to become less negative and depolarized. Depolarization spreads to adjacent areas; opening voltage gated sodium channels that initiates an action potential. Na+ concentrations caused bu depolarization opens up voltage gated K+ pumps starting a re polarization process.