Vertebrate Skeletal Muscle

Abstract

In the main part of this chapter an account is given of the information available on the structure of the sarcomere in vertebrate striated muscle. The particular example most commonly quoted here is the sartorius muscle of the frog. It must be recognized, however, that this muscle, although probably the most extensively studied vertebrate skeletal muscle, is actually rather a specialized example. Different skeletal muscles in the same animal, different fibers in the same muscle, and analogous muscles in different animals can have markedly different properties, and many of these appear to be associated directly with the ultrastructure of the sarcomere. The sarcomere of the frog sartorius muscle will therefore be used as a kind of standard against which the structures of other vertebrate skeletal muscles (where these are known) can be compared.