01:377:370 Lecture Notes - Lecture 19: Alpha Motor Neuron, Neuromuscular Junction, Resting Potential

• School: Rutgers University
• Department: Exercise Scienc
• Course: 01:377:370
• Professor: S Arent

Document Summary

The number of muscle fibers per motor neuron is related to a muscles function. Large muscles may have as many as 3000 fibers/neuron. Motor unit: one motor neuron and the specific muscle fibers it innervates. Motor neuron pool describes the collection of alpha motor neurons that innervates a single muscle. Fiber:motor unit ratio differs for fine vs gross movement. Axon ( extends from spinal cord to deliver impulse to muscle) Dendrites (short neural branches that receive impulses and conduct them to cell body) Myelin sheath: lipoprotein membrane that wraps around the axon. Represents the interface between the end of a motor neuron and a muscle fiber. The ap stimulates the sac-like vesicles at the nmj to release ach. Ach binds to a receptor on the postsynaptic membrane. Ap travels the length of the sarcolemma entering the t-tubule system. Ach binds to receptor sites changing the membranes permeability to na+ ions.