TOPICS: Corticospinal tract, alpha motor neurons, muscle stimulation, ventral horn, spinal cord, acetylcholine (Ach), depolarization, repolarization, sodium (Na+) channels, calcium (Ca2+) channels, synaptic cleft, neurotransmitter, nicotinic acetylcholine receptors, sarcolemma, T-tubule, sarcoplasmic reticulum, ryanodine receptor, troponin C, tropomyosin, actin, myosin, sarco-endoplasmic reticulum calcium transport ATPase (SERCA), calsequestrin