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2010-10-30 15:37:37
chapter part

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  1. fascia
    bundle of muscle fibers (dense)
  2. Tendons
    cordlike layer of connective tissue
  3. sarcomere
    function of muscle fibers
  4. myofibril
    bundel of filaments
  5. z line
    separates sarcomeres (protine that borders)
  6. cross bridge
    bridge between myosin & actin
  7. motor nueron
    stimulates muscle- nerve cell that goes to muscle
  8. muscle tone
    continuous partial state of contraction
  9. thereshold stimulus
    minimum stimuls for a nueron to make a muscle contract
  10. describe the 4 characteristics of muscle tissue
    • excitability- recieve & respond to a stimulus
    • extensability- stretch beyond normal
    • contractibility- shorten & thicken within stimulus is recieved
    • elasticity- return to origional shape after extension or contraction
  11. describe the 3 functions of muscle tissue
    • motion- whole or localized
    • maintance of posture- maintains position
    • heat production- enzymes function best at a certian temp and the body heat is from muscle contraction
  12. what advantages are there to a) whole body movement b) localized movement
    • a) from one place to another
    • b) movement of one part
  13. how are the fibers of skeletal muscle different from that of cardiac muscle?
    • skeletal- striated, voluntary, movement of skeleton
    • cardiac- heart, less striated, involuntary, pump blood
  14. what does the term smooth refer to in smooth muscle
    no striations
  15. which types of muscles are voluntary?
  16. what types of tissues are muscles composed of?
    • muscle
    • connective
    • nervous
    • vascular
  17. relationship between: epimysium, perimysium, and endomysium
    • epimysium- covers entire muscle
    • perimysium- covers bunches of fibers
    • endomysium- covers individual fibers (cells)
  18. the outward extension of these froms what?
  19. what is the purpose of the tendon sheaths?
    • to protect tendons
    • reduce tension
    • allignment of rind tissue
  20. what is tendenitis
    inflamation of tendon sheaths
  21. what part of a muscle is considered to be the muscle cell?
    muscle cell (fibers)
  22. why does a single muscle cell have many nuclei and mitochondria?
    • length
    • long and thin (more energy)
  23. do myofibrils and myofilaments run the entire length of a muscle cell?
    myofibrils YES

    myofilaments NO
  24. what are the differences between the myosin and the actin myofibrils?
    myosin- thicker, entensions mosin

    actin- thin myofilaments zlines
  25. what are troponin and tropmyosin, where are they found and what is their function?
    protines associated with actin and myofilaments, prevents the binding of actin & myosin myofilaments by blocking myosin binding sites, found around actin
  26. what are the striations on skeletal muscle due to?
    • alterating actin and myosin regions
    • light/dark bands
    • actin- thin myosin- thick
  27. what is the function unit of a muscle cell?
  28. what is the function of acetylcholine and where is it produced?
    nuerotrans mitter that alters heart contractions causing an impulse by duffusing across muscle

    produces axon ends that stimulate muscle
  29. why to the motor nuerons of the eye innervate less muscle fibers?
    fine motor control
  30. why arent all the muscle fibers of a muscle fired at the the same time
    stamena ( so that other muscle fibers can rest)
  31. what is the function of muscle tone?
    • posture
    • coordination
    • joint stability
  32. when a nervous impulse reaches the end of a motor anon what occurs?
    acetylcholine is released (which diffuses across the neuromuscular junction and combines with recptor sites on the sarcolemma of the muscle fibers)
  33. when a muscle is stimulated by nerve what happends to the sarcolemma and the transverse tubules?
    acetylcholine diffuses an impulse alone the sarcolemma membrane and than the impulse travels down the transverse tubules
  34. as a result of number 28 what next happends in the muscle and what is the result of this?
    release of calcium ions combines with tropomin and tropomyosin causing them to move which result in the exposure of myosin binding sites on the actin
  35. when a myosin head comes in contact with a myosin-binding site on the actin, what happens?
    releases energy, swivels/ bends to pull an actin myofilaments and the additional energy is released and give the myosin heads new energy
  36. what happends to the length of a sarcomere during contraction and extension?
    it shortens & lenghtens
  37. what terminates a contracrtion?
    absorption of calcium ions and transport back into the sacroplasmic reticulum for storage
  38. why does the body stiffen up after death?
    muscle tone
  39. Can muscle cells partially contract?
    NO thereshold
  40. Can muscles partially contact?
    yes depends on # muscle fibers contract or dont (all or nothing)
  41. describe the 4 types of muscle contractions
    twitch- one brief contraction, stimulus

    tetanus- sustained contraction (results)

    isotonic- contraction of a muscle under same tension

    isometric- same length tension may increase not moving body parts
  42. most of the work you do with your muscles is of what type?
    isometric and isotonic combination
  43. lifting a weight is what type of contraction?
  44. trying to lift a weight is what type of contraction?
  45. what is atrophy, what is it due to, and what is the result of it?
    • breakdown and weaking of muscle due to lack of use
    • become weaker
  46. slow twitch
    lots of myoglobin (RED)

    contract slower

    endurance (long distant running)
  47. fast twitch
    low in myogobin (white)


    powerful brief contractions
  48. fast twitch fatigue resistant
    lots of myoglobin (RED)

    attract quickly (less endurance)

    forceful sustained brief contraction sprinter
  49. endurance exercises
    repitive running

    bring heart rate up to 50% of max heart rate

    benefits: increase capalaries, increase midocondria= more atp, more myoglibin produced
  50. resistance exercises
    not repitive, running laps

    exerting 75% max

    increase amount of actin and myosin

    making muscle stronger
  51. what affect does aging have on muscles
    lose muscle tissue (age 30)