Smooth, striated, and cardiac are the three classifications of muscle in mammals. Anytime someone waves hello or taps their foot in time with music on the radio, they are utilizing striated muscles

View a second image of a striated muscle thin section.

Striated muscles are sometimes alternatively referred to as voluntary, striped, or skeletal muscles. The fibers of the muscle group, composed of actin and myosin filaments, are long, thin, and marked with a characteristic pattern of red and white bands. The muscle cells are large and striated muscle is the most common muscle type in vertebrates. Bundled together in cords, striated muscles are connected to bones by tendons and have the ability to rapidly contract. Directly controlled by the central nervous system, voluntary impulses cause the striated muscles to become active.

In addition to movement, muscles are important for their generation of body heat. In order for muscles to function, they require chemical energy produced from the metabolism of food. When a muscle is active, part of the chemical energy is used for work and part is converted to heat. The heat produced is crucial for the survival of warm-blooded animals. In fact, when a body shivers from cold, it is creating its own movement in order to generate sufficient warmth.