Wikimedia Commons has media related to Muscular system.

The muscular system is the biological system of animals (including humans) that allows them to move internally and externally. The muscular system in vertebrates consists of three different types of muscles: cardiac, skeletal and smooth. Cardiac muscle is a striated muscle that makes up the heart. It is the only type of muscle consisting of branching fibers. Skeletal muscle consists of voluntary muscles attached to the frame of the skeletal system enabling bodily movement. Smooth muscle is the involuntary muscle that enables the movement of internal organs. Movement of all muscles is controlled through the nervous system.