A baby has more than six hundred muscles. In addition to locomotion, muscles perform a number of functions associated with digestion, respiration, circulation, excretion and reproduction. The body contains three distinct types of muscles.
(1) Smooth muscles: These occur primarily i the wall of internal organs. They are spindle-shaped cells.
(2) Skeletal muscles: Also called striated, voluntary or somatic muscles. These contract most rapidly and vigorously.
(3) Cardiac muscles: These form a unique type of muscular tissue found only in the heart. They resemble with the skeletal muscles in being made up of striated multinucleated fibres.