There are three types of muscles in your body: striated, non-striated, and cardiac. Food moves through intestines and blood moves through blood vessels via the contractions of smooth or non-striated muscle.
The heart, a continually working muscle, beats because of specialized cardiac muscle. Muscles that facilitate movement, like your biceps or abdominals, are skeletal or striated muscles.
One of the major differences between smooth (or non-striated muscles) and cardiac or striated (skeletal) muscles is how they contract. Smooth muscles are said to constrict or dilate, while cardiac and
striated (skeletal) muscles contract (shorten) or relax (lengthen). Constriction and dilation are still contractions, but of hollow organs such as your intestines.