EXPERIMENTAL STUDY ON INNERVATION OF THE SKELETAL MUSCLE

1) The skeletal muscle is supplied by four varieties of nerve fibres. In the striated musele fibre, the moderately myelinated and unmyelinated nerve fibres are found. The former constitute the typical motor network in the muscke fibre. In the muscle spindle, the heavily myelinated ( afferent ), moderately myelinated ( efferent ) and unmyelinated nerve fibre are found. Coursing the blood vessels the unmyelinated and slendely myelinated nerve fibres are found. 2) The moderately myelinated nerve fibre may play an important part in producing atrophy of the denervated muscle, and the unmyelinated nerve fibre may have no close relation with it. 3) Disuse atrophy of the muscle may be caused by matabolic disturbance of the muscle due to its inactivity, and although slight moephological changes in the nerve fibres are present, they do not take part in producing this muscular atrophy. 4) It may be thought that the unmyelinated nerve fibre play an important role in producing so-called ischaemic contracture.