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Download MUSCLE!!! KNR 480
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Chris, Cory, Taylor, Vince KNR 480 Each skeletal muscle is an organ that contains: ◦ ◦ ◦ ◦ Muscle Tissue Connective Tissue Nerves Blood Vessels Each muscle is surrounded by fibrous connective tissue, called the epimysium. Under the epimysium are bundles of muscle fibers called fascicles. Each fascicle may contain up to 150 individual muscle fibers and is surrounded by a layer of connective tissue called perimysium. Each individual muscle fiber is surrounded by yet another layer of connective tissue, the endomysium. The muscle cells (sometimes referred to as muscle fibers, myofibrils, or myocytes) are cylindrical in shape and have many nuclei located on the outer layer of each cell. The sarcoplasm (the cytoplasm of a muscle fiber) contains contractile proteins (myofilaments) called actin and myosin. In addition to the protein structures of muscle, muscles also hold water (varies with hydration status), stored glycogen and fat particles, enzymes, and organelles such as mitochondria and the sarcoplasmic reticulum. A study by Janssen, Heymsfield, Wang, and Ross looked at skeletal muscle mass and distribution in 468 adult (18-88 years old) men and women. They found that… Muscle mass: ◦ Men - 38.4% of total body mass ◦ Women - 30.6% of total body mass Muscle can be found all over the body! It covers the skeleton of the body to protect and stabilize bones and joints. It attaches to the skeleton by tendons or is directly attached to rough patches of the bone (aponeurosis). It can also attach directly to the skin. ◦ Example: Muscles in the face. Baechle, T. R., & Earle, R. W. (2008). Muscular, neuromuscular, cardiovascular, and respiratory systems. In Essentials of Strength Training and Conditioning (3rd ed., pp, 4-19). Champaign, IL: Human Kinetics. Janssen, I., Heymsfield, S. B., Wang, Z. M., & Ross, R. (2000). Skeletal muscle mass and distribution in 468 men and women aged 18-88 yr. J Appl Physiol, 89(1), 81-8. http://www.bbc.co.uk/science/humanbody/factfi les/skeletalsmoothandcardiac/heart_beat.shtml
