ACB 406.3 Lecture Notes - Lecture 5: Collagen, Microglia, Muscle Spindle
Document Summary
With the exception of flagella and cilia and gravity, muscle is responsible for all mechanical processes in the body. Classified by microscopic appearance of its contractile cells: skeletal, smooth and cardiac. Skeletal muscle = composed of extremely long cylindrical multinucleate cells (fibers: striated appearance, multinucleated, voluntary control, muscle fibers are held together by connective tissue. Muscle = group of fascicles surrounded by epimysium. Muscle fascicle = group of fibers surrounded by perimysium. Muscle fiber = a muscle cell surrounded by endomysium. Sarcomere = the basic contractile unit of muscle. Many sacromeres aligned longitudinally form a myofibril. A sarcomere consists of overlapping actin and myosin filaments that interact to cause contraction: appear as a striation. Skeletal muscle fibers are held together by ct that transmits the force of contraction. Carries capillaries & small nerve fibers membrane around each fiber. Carriers larger blood vessels, nerves, neuromuscular spindles, lymphatics. Endomysium, perimysium and epimysium coalesce at attachments.