BPK 105 Lecture Notes - Lecture 3: Skeletal Muscle, Muscular System, Muscle Tone
16 Jun 2016
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Document Summary
Most of movement is credited to muscle contraction. Skeletal muscles: muscles attached to the skeletal system, composing ~40% of body weight. Muscle fiber structure: muscle fiber: cylindrical fiber with many nuclei at the periphery, sarcolemma: cell membrane of a muscle fiber, transverse tubules: (t tubules) invaginations on the surface of the sarcolemma; extends inwards into the muscle fiber. Connects the sarcolemma to the sr: sarcoplasmic reticulum: (sr) highly organized smooth er that stores high. [ca2+: sarcoplasm: cytoplasm of the muscle fiber, contains many myofibrils, myofibrils: thread-like structures that extend from one end of a muscle fiber to the other. Actin myofilaments: thin filaments arranged into 2 pearl strings wrapped around e/o, contains myosin binding sites: contains: Myosin myofilaments: thick myofilaments arranged into bundles of golf clubs, containing myosin heads that bind to myosin binding sites on actin myofilament: myosin heads have 3 properties: They bind to attachment sites on actin myofilaments. They break down atp to release energy.
