How are muscles the contractile specialists of the body?

Muscle cells are uniquely adapted to contractile function due to three main things. FIrst, they have a large capacity for storage of readily available glycogen to use for work. Second, they contain the actin and myosin cross-bridge cycling structure to perform a contraction of a muscle fiber. Finally, each fiber has central nervous innervation to control contraction and relaxation of the muscle fibers.