CH 10 muscular system structure and function regional muscles

muscle functions movement = move body, parts, contents, communication stability = posture, tone, openings = mouth, urethra, sphincters, light, cervix heat = production, 85% from skeletal sugar = muscles absorb, store, use, glycemic control

fusiform = strong parallel = shortens the most triangular = strong unipennate = strong bipennate = stronger multipennate = strongest circular = weak to strong

muscle coverings fascia = connective tissue sheet which separates neighboring muscle groups, compartments = functionally related muscles separated from each other by fascia, some very thick called intermuscular septa epimysium = fibrous connective tissue which surrounds a muscle perimysium = thick connective tissue which wraps muscle fibers together to form bundles of fibers called fascicles endomysium = thin loose connective tissue sleeve which surrounds individual muscle fibers, in a fascicle

tendons and muscles indirect = muscle ends short of bony attachment aponeurosis = tendon is a broad sheet direct = muscle ends so close to bone it is as if it originates from bone origin = where muscles tendon attaches to relatively stable bone insertion = where muscle attaches to a more mobile bone prime mover (antagonist) = produces most force during a movement synergist = muscle aids prime mover antagonist = muscle opposes prime mover fixator = muscle holds a bone steady intrinsic = muscle entirely contained within a particular region extrinsic = muscles act in one area but origin is elsewhere

muscle function nutrients via blood vessels – caps undulate/coil for stretch activity via nerves – spinal and cranial nerves - motor and sensory

Rest of chapter deals with specific muscle groups functioning to perform specific tasks and will be dealt with in lab