[Fr., from L. musculus.] The fleshy parts of the body, which have the power of contracting and of moving the joints with which they are connected. Muscles are striated and voluntary, or non-striated and involuntary. They are composed of fibres laid side by side, forming bundles, which are attached to the bones by tough whitish strings called sinews or tendons. The various bones of the body are moved by about 400 muscles.