PHGY 209 Lecture Notes - Lecture 7: Hydrolysis, The Motor, Chemical Synapse
17 Mar 2017
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3 types of muscles: skeletal muscle, used for posture & locomotion, muscle that enables ours arms & legs to contract, under our conscious control, cardiac muscle, responsible for rhythmic contractions of heart (automatic, smooth muscle: Involuntary contractions in blood vessels, gut, bronchi, & uterus: controlled by autonomic nervous system. Skeletal muscles: muscle attached at each end to tendons tendons attach to bone on both sides of a joint, contraction of skeletal muscle pulls on tendons resulting in flexion of joints. ** important: muscles can only contract (shorten) or relax (elongate) range of motion depends on how they are connected to bones. Composition: bundles of long (up to 1 ft), thin cells called muscle fibers. Muscle fibers: consist of cylindrical bundles (also fibers) called myofibrils. Aka: muscle fiber (cell) is filled w/ more long fibers (myofibrils) All myofibrils lined up again enables myofibrils to act as single, coordinated unit.
