Physiology of Finfish and Shellfish (2+1)

3.2.3. The muscle fibre

Living muscle is composed of many long, cylindrical staped fibres from 0.02 to 0.08 millimetres in diameter. In some muscles, the fibres run the entire length of the muscle, upto several centimeters long. In others, a tendon extends along each edges and the fibres run diagonally across the muscle between the tendons. The fibres in living muscle appear transparent when viewed in an ordinary optical microscope. A series of alternative dark and bright bands can also be seen. In chemically prepared and stained sections of muscle, each fibre is surrounded by a rather complex, multilayered structure, the sarcolemma. The outermost layer is the fine network of fibrils, which at the ends of the muscle extend into tendons and form structural line with them. The next laser is the sakolemma is a foundation membrane. The inner most is the plasma membrane. Sarcoplasm is the special name for cytoolasm of a muscle fibre. Each striated muscle has a nucler.