The ultrastructure of striated muscle.

Striated muscle is a tissue in which the major cytoplasmic components are spatially arranged to produce directional motion. This orientation is seen at all levels of structure, beginning with the molecular placement of characteristic proteins into 2 dissimilar types of filaments, and proceeding ultimately to the alignment of muscle fibers in the heart or an anatomically defined skeletal muscle. Generation of contractile force is accomplished by the enzymatic interaction of the 2 dissimilar protein filaments, which results ultimately in the utilization of energy (in the form of adenosine triphosphate) and the production of directional motion.