Muscle: Cell Types Composing the Tissue

Muscle, a tissue responsible for motion in the body, is derived from the Latin musculus (little mouse) because of its appearance under the skin. Muscles are formed by a process, called myogenesis, during embryogenesis.

Vertebrates have three major groups of muscles, classified as striated, including both the skeletal and the cardiac muscles (semi-striated); and smooth muscles, each adapted uniquely for its own function in different organs and structures.

A single cell of the muscle is called a myocyte. This cell varies in the three major types of muscles by the difference in composition or presence of the myofibrillar contractile protein filaments (i.e., myofilaments). Also striated muscles contain sarcomeres required for short contraction intervals, unlike smooth muscles that lack these, and thus their period of contraction is prolonged.

The ...