Name Class Date 32.2 The Muscular SystemLesson ObjectivesDescribe the structure and function of each of the three types of muscle tissue.Describe the mechanism of muscle contraction.Describe the interaction of muscles, bones, and tendons to produce movement.Lesson SummaryMuscle Tissue About one third of the mass of the body is muscle. There are three different types of muscle tissue.Skeletal muscle, which has alternating light and dark bands called striations, makes up muscles that are usually attached to bones. Movements of most skeletal, or striated, muscle are consciously controlled by the central nervous system. The cells in skeletal muscle are often called muscle fibers.Smooth muscle, which lacks striations and is made up of spindle-shaped cells, lines the walls of hollow structures such as the stomach and blood vessels. Movements of smooth muscle are usually involuntary.Cardiac muscle, which is also striated but has smaller cells than skeletal muscle, is found only in the heart. The control of cardiac muscle is involuntary.Muscle Contraction Skeletal muscles produce movements by contracting from end to end. The contractions result from the interaction of two kinds of muscle protein filaments—actin and myosin.