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Muscle attachments
Question | Answer |
---|---|
Origin | stationary, immovable attachment of muscle to bone |
Insertion | movable attachment of muscle to bone |
Abduction | limb away from median plane |
Adduction | Limb toward median plane |
Flexion | decreace joint angle, brings bones closer |
Extension | increase joint angle, bones farther apart |
Rotation | Circle |
Circumduction | Cone |
Skeletal Muscle | 1. Striated or voluntary 2. Conprises the bulk of the body's muscles 3. attached to skeleton or associated connective tissue |
Cells of Skeletal muscle | 1. relatively large 2. multi-nucleited 3. long & cylindrical 4. Sarcolemma 5. Sarcoplasm 6. Also called fibers 7. Ranges from 10 microm- 6cm |
Sarcomere | 1. contractile unit 2. goes form one Z line to the next 3. Actin 4. Myosin |
Actin | thin filamentboth light & dark |
Myosin | thick proteinonly in the dark band |
Endomysium | encloses muscle fibers delicate, areolar connective tissue sheath |
Perimysium | a collagenic membrane sheaths muscle fibers forming a bundle of fibers called fascicle |
Epimysium | sheaths the entire muscle large number of fascicles are bound togethervery coarse |
Tendons | tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tesion |
Aponeurosis | 1. sheetlike tendinous expansion, serving to connect a muscle with the parts it moves 2. attach muscles to each other or indirectly to bones |
Motor unit | a neuron and all the muscle cells it stimulates |
Synaptic cleft | a small fluid-filled gap that separates the neuron and muscle fiber membranes |
Acetylcholine (ACh) | neurotransmitter chemicleallows change in the permeability of the sarcolemma |
Vesicles | store various neurotransmitters |
Agonists | prime moversresponsible for producing a particular movement |
Antagonists | oppose or reverse a movement |
Synergists | aid the action of agonists |
Fixators | specialized synergists |
Retus | Direction of fibers |
Maximus | Size |
Frontalis | Location |
Biceps | number of origins |
Sternocleidomastoid | location of origin and insertion |
Trapezius | shape |
Adductor | Action |