PLN 103 Lecture Notes - Lecture 9: Muscle Fascicle, Skeletal Muscle, Sarcolemma
13 Dec 2016
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Pln week 9 muscle system part i. Types of muscles: cardiac, smooth, and skeletal muscle. Cardiac heart wall, involuntary, striated muscle with intercalculated discs connecting cells for synchronized contractions during heart beat. Smooth organ and blood vessel walls, involuntary, spindle-shaped cells for pushing things through organs. Skeletal large body muscles, voluntary, striated muscle packed in bundles and attached to bones for movements. Functions of skeletal muscle: produce skeletal movement, maintain posture & body position, support soft tissue, guard body entrances & exits, maintain body temperature, store nutrients. Striations thin (actin) and thick (myosin) filaments. Multinucleate genes control enzyme and structural protein production that control contractions. Myoblasts fuse in development to form multinucleate skeletal muscle fibres. Myosatellite cell are myoblasts that did not fuse (used in injury) Structural organization: skeletal muscle belly, muscle fascicle, muscle fibre, myofibril, sarcomere. Epimysuim dense collagen fibres surrounding entire muscle. Perimysium divides skeletal muscle into series of compartments (fascicle) Endomysium surrounds individuals muscle fibres and contains:
