The flattened contact site, or neuromuscular junction, between a nerve cell and a striated muscle fiber, with each fiber forming one end plate. Also known as a motor plate, It synapses with the bouton of a motoneuron and is in essence a modification of the overlying sacrolemma, with which it is continuous (the sarcolemma being a thin, transparent membrane that covers every striated muscle fiber, its outer layer fusing with tendon fibers). It has deep creases, referred to as functional folds, which serve to increase its surface area and thereby the number of available ACh receptors. Each nerve impulse releases a ‘spurt’ of acetylcholine that results in the graded summation of small depolarizations to some critical threshold, and that in turn results in the generation of an action potential that travels along the muscle.
See Acetylcholine (ACh), Action potential, Boutons, Dorsal root ganglia (DRG), Motoneuron, Muscle fiber, Musculoskeletal system, Neuromuscular junction, Neurotransmitters, Striated (or striped or voluntary) muscle, Synapse