Skeletal Cell Structure Human body contains over 400

Skeletal Cell Structure

Human body contains over 400 skeletal muscles 40 -50% of total body weight Functions of skeletal muscle Body movement (Locomotion) Maintenance of posture Respiration Diaphragm and intercostal contractions Communication (Verbal and Facial) Constriction of organs and vessels Production of body heat (Thermogenesis)

Epimysium Surrounds entire muscle Perimysium Surrounds bundles of muscle fibers Endomysium Surrounds individual muscle fibers

• Epimysium is fibrous elastic tissue that surrounds each muscle. Fasciculus is a small bundle of muscle, tendon, or nerve fibers wrapped by a layer of connective tissue called the perimysium (muscle) or perineurium (nerve fiber).

• Perimysium is the name given to the fibrous sheath that surrounds (covers) each bundle of single muscle fibers, the bundle being known as a fascicle. Endomysium is the delicate connective tissue surrounding the individual muscular fibers within the smallest bundles

• Sarcolemma is the name of the cell membrane that encloses each muscle cell. Each muscle fiber itself contains cylindrical organelles known as Myofibrils.

The Epimysium protects the muscle from friction against other muscles and bones. It also continues at the end of the muscle to form (along with other connective tissues) the muscles tendon.

Looking at the cross section of the muscle you can see bundles of fibres / fibers, known as Fasciculi, which are surrounded by another connective tissue, called the Perimysium.

Endomysium insulates each muscle fiber. Beneath the Endomysium and surrounding the muscle fibre is the Sarcolemma and beneath this is the Sarcoplasm, which is the cells cytoplasm

Sarcoplasm contains Glycogen and Fats for energy and also Mitochondria Each muscle fiber contains hundreds to thousands of Myofibrils. These are bundles of Actin and Myosin proteins which run the length of the muscle fiber and are important in muscle contraction.

Surrounding the Myofibril there is a network of tubules and channels called the Sarcoplasmic Reticulum in which Calcium is stored which is important in muscle contraction.