What are the structural and functional differences between skeletal, smooth and cardiac muscles and where are they found?
Skeletal muscle is the type normally thought of when one thinks of the word muscle, but do not be mislead, this is only one of three different types of muscle. The three different muscles, classified by their general microscopic appearance, are skeletal, cardiac and smooth. Let’s start first with skeletal. Skeletal muscle is characterized by elongated, multi-nucleated fibers, or cells, with striations due to light, I band, and dark, A band, alternations. The nuclei of the fibers are not centered, but rather located towards the outer edge of the cells. These muscles are under somatic or voluntary control. This means they are under immediate conscious control by the nervous system. Skeletal muscle has a name related to its function since it is usually associated with attachment to and movement of bones and cartilage. Skeletal muscle requires either extrinsic nerve or hormonal stimulation to create action potentials, which trigger movement. Cardiac, like skeletal muscle, is also striated.
