What is the correct order of steps in muscle contraction?

Answer 1

first nerve impulse comes to neuromuscular joint then neurotransmitter acetylcoline release to synaptic cleft and depolarize the muscular joint then ca released from

sarcoplasmic reticulum and make the tropomyosin to remove from binding place with myosin then myosin pull the actin and they overlap on each other h band disappear but a band remines untact howerver i bands become shorter,after removing the nerve impulse the ca pumped back to sarcoplasmic reteculum and the lenght of muscle return to same position