Transport of materials within the body. Nearly all cells contain actin and myosin, two contractile proteins, that generate force, and produce movement. Muscle cells, in contrast, are specialized contractile units that contain large, organized arrays of actin and myosin under precise regulation. They function as multi-cellular contractile units. The three types of muscle are skeletal, cardiac, and smooth .
Skeletal muscle moves the skeleton and organs like the tongue and eye.
It is under voluntary control. Its highly organized contractile proteins give a striated appearance. Cardiac muscle generates the rhythmic contractions of the heart. It is also striated. Smooth muscle does not have a striated appearance since its contractile apparatus is organized differently from that of the other muscle types.