Write out the steps needed for a skeletal muscle to contract. Include these terms in your write up: neuromuscular junction, somatic motor neuron, acetylcholine, acetylcholinesterase, sarcolemma, motor end plate, synaptic knob, synaptic cleft, ligand-gated sodium channel, action potential/depolarization, t-tubules, sarcoplasmic reticulum, Ca2+ ions, voltage-gated calcium channels, troponin, tropomyosin, actin active sites, myosin head, ATP, hydrolysis of ATP, cross-bridge formation, sarcomere shortening