Illustration of the ultrastructure of a neuromuscular synapse (longitudinal section through one branch of an end plate cluster). The pre-synaptic element is filled with synaptic vesicles (SV). The surface area of the synaptic cleft is greatly increased by junctional folds (JF). The muscle sole plate is colored brown. The surface of the end plate is covered by lemmocyte cytoplasm (green) and basal lamina.