This document summarizes the structure and function of the neuromuscular junction, where motor neurons connect to muscle fibers to enable muscle contraction. It describes how action potentials in the motor neuron cause the release of acetylcholine (Ach) vesicles at the presynaptic terminal. Ach then diffuses across the synaptic cleft and binds nicotinic Ach receptors on the postsynaptic muscle membrane, generating an endplate potential. If this potential exceeds a threshold, it triggers an action potential in the muscle fiber, causing muscle contraction. The transmission process is terminated by the breakdown of Ach by acetylcholinesterase in the junction.

1. By: Dr. Swathi Prof Dr A.Gowrishankar’s unit

21. T H A N K U