ATROPHY IN SKELETAL MUSCLE

Abstract

Mammalian skeletal muscle is served by a number of different types of nerve fibers. Some represent the central and others the autonomic nervous system. Diagrammatic representation of the component parts of skeletal muscle innervation has been attempted in figure 1. Probably only the motor nerve fibers, axons of the lower motor neuron, make functional connection with the muscle fibers. It is generally believed that these fibers, and these alone, are responsible for the control of the activity of the muscle fiber and are chiefly responsible for the trophic state of muscle tissue. Boeke¹ and others have claimed that muscle fibers are also innervated by autonomic nerve fibers. Such connections may exist, but there is no satisfactory evidence that the autonomic nervous system has any direct control over the activity of skeletal muscle fibers. Sympathetic and parasympathetic nerve fibers to blood vessels in muscle give the autonomic nervous system indirect