The NMJ is the site where nerves originating from the spinal cord innervate muscle fibers. The junction consists of the nerve terminal ending, the motor fiber and a Schwann cell. The nerve terminal is responsible for transmitting the signal generated from the central nervous system to individual muscle fibers. It communicates with the muscle by releasing neurotransmitters which can depolarize the motor fiber membrane. Axons lose their myelin, which is created by the Schwann cell to help improve conduction and insulate the cell, before arriving at the NMJ.
References:
1. Neuromuscular Blocking Agents. In Morgan, G. E., Mikhail, M. S., & Murray, M. J. Clinical anesthesiology. New York, NY: Lange Medical Books/McGraw Hill Medical Pub; 2006: 200-204.
2. Martyn JA, Fagerlund MJ, Eriksson LI. Basic principles of neuromuscular transmission. Anaesthesia. 2009;64 Suppl 1:1-9. doi:10.1111/j.1365-2044.2008.05865.
