At the terminal end of the axon is a branched structure with ends called synaptic knobs. From this structure chemical signals can be sent to neighboring neurons. Transmission of nerve impulse along the axon
When an action potential reaches the axon terminal of a motor neuron, vesicles carrying neurotransmitters (mostly acetylcholine) are exocytosed and the contents are released into the neuromuscular junction.These neurotransmitters bind to receptors on the postsynaptic membrane and lead to its depolarization.he small depolarization associated with the release of acetylcholine from one synaptic vesicle is called a miniature end-plate potential (MEPP). MEPPs are additive and lead to a greater depolarization of the postsynaptic membrane and become end plate potentials (EPPs).
In general, the term vesicle refers to a small sac or cyst that contains fluid or gas. In cell biology, vesicle refers to the bubble-like membranous structure that stores and transports cellular products, and digests metabolic wastes within the cell. The cell forms vesicles during exocytosis, endocytosis, and intracellular transport. Vesicles may be produced artificially and are referred to as lyposomes. Some of their functions are associated with metabolism, transport, storage of food and enzymes, and buoyancy. There are different forms of vesicles: vacuoles, lysosomes, transport vesicles, secretory vesicles (e.g. synaptic vesicles), extracellular vesicles (e.g. exosomes, microvesicle, etc.), and gas vesicles. Word origin: Latin vÄsÄ«cula, diminutive of vÄsÄ«ca, bladder, blister See also: organelle; Related term(s): Neurotransmitter vesicle; Biliary vesicle