# data[].attributes.body
Step 4: energy from hydrolysis of ATP "cocks" myosin head into high-energy state

# data[].attributes.body
Step 3: ATP attaches to myosin head, causing cross bridge to detach

# data[].attributes.body
step 2: The myosin head pivots and pulls actin filament toard m line

# data[].attributes.body
step 1: High energy myosin head attaches to actin myofilaments forming a cross bridge

# data[].attributes.body
Step 3 and 4: The Ca2+ combines with the troponin and removes the blocking action of tropomyosin by changing its shape. The cross bridges

# data[].attributes.body
Step 2: The t tubules cause the adjacent sarcoplasmic reticulum to release Ca2+ which flows into the cytosol

# data[].attributes.body
Step 1:  Action Potential travels down the sarcolemma and the t tubules

# data[].attributes.body
Summarize steps of event 1 using the following words: Acetycholine, Calcium ions, action potential, axon terminal, sarcolemma,  voltage-gated Na+ ion channels, voltage-gated K+ ion channels, depolarization, repolarization, Na+ ions and K+ ions.