A&P 1 exam 2 (part 7)

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A&P 1 exam 2 (part 7)
2014-10-13 19:10:40
fall 2014

Muscle Microanatomy cont Fall 2014
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  1. where is z-line found?
    right in middle of I-band
  2. I-band is ?
    light band
  3. a-band is?
    dark band
  4. where are a-bands found?
    towards the center
  5. thick?
  6. thin?
  7. where are thin filaments found?
    in both dark and light bands because they overlap with thick filament s
  8. what are pulled closer together during contraction?
  9. when z-bands are pulled closer together, what happens?
    shortens length of sarcomere
  10. which band is reduced in length during contractions of striated muscle?
  11. what happens to a-bands during contraction?
    there is no change
  12. during contraction?
    • z line is pulled towards center
    • no change in thick filaments
  13. as z-line moves towards center, I-bands ____ but a-bands _____ ___ ___
    • shorten
    • stay the same
  14. what is important for contraction in striated muscle?
    sarcoplasmic recticulum
  15. sarcoplasmic recticulum is aka
    smooth ER for a muscle fiber
  16. what is sarcoplasmic recticulum used for?
    storage area
  17. what does sarcoplasmic recticulum store?
    it stores calcium ions
  18. what do calcium ions act as?
    triggers for contractions
  19. what happens when calcium ions are exposed?
    calcium interacts with myofilaments
  20. when there is not calcium present?
    muscle is relaxed
  21. what is the interior of cell filled with?
    sarcoplasmic recticulum
  22. what initiates release of calcium ions?
    nervous system
  23. what does the sarcolema do with calcium ions?
    it produces an electrical impulse that releases calcium ions to lead sarcomplasmic recticulum powered by diffusion gradient
  24. the cell membrane becomes ____ to __ __
    • permeable
    • calcium ions
  25. what happens when calcium floods to outside?
    it causes sarcomeres to contract
  26. associated with sarcoplasmic recticulum
    transvere tubules (t-tubules)
  27. 1 region of sarcoplasmic recticulum
    lateral sac
  28. what is a triad?
    a t-tubule and 2 lateral sacs
  29. what goes through out cell itself?
  30. what do triads ensure?
    that all contract at the same time
  31. how do you stop muscle contractions?
    get rid of calcium by putting it back into sarcoplasmic recticulum
  32. whens stopping muscle contractions, calcium must?
    go against concentration gradient by using active transport
  33. it costs energy to cause muscle fiber to
  34. it takes energy to ___ and stop ____ in muscles
    • contract
    • contraction
  35. muscles are ready to ____ all the time
  36. arrangement of fibers in striated muscle?
  37. each individual cell in striated muscle is wrapped with
    connective tissue
  38. 3 types of connective tissue in striated muscle
    • endomysium
    • perimysium
    • epimysium
  39. wraps individual muscle fibers and provides insulation
  40. wraps entire fascicle
  41. wrapped around entire muscle itself (organ)
  42. _____ is continuous with periosteum which is continuous with _____
    • endomysium
    • epimysium
  43. why is connective tissue needed?
    to get force to skeletal system from contraction
  44. continuation of all connective tissue, which attaches to bones
  45. what is continuous with tendon?
  46. the diameter of ____ is smaller than diameter of ____
    • tendon
    • muscle
  47. why is having tendons with small diameters helpful?
    allows you to apply a lot of force to a big area with out having the big muscle right there
  48. ex of helpful small tendon diametes?
    fingers, muscle in forearm move fingers, the force goes through small tendons making fingers still have great strength
  49. skeletal muscle contracts?
    • much more quickly
    • has more speed, high velocity
  50. during contraction, skeletal muscles?
    consume a lot more energy and can fatigue relatively easily and quickly
  51. contraction in skeletal system starts via?
    nervous system, consciously control contractions
  52. only way to initiate contraction in skeletal is by?
    from nervous system
  53. voluntary muscle?
    skeletal (striated)
  54. in skeletal muscle, the fibers contract from what lengths?
    1/2 to 2/3 of resting length
  55. where is cardiac muscle found?
    embedded in wall of heart
  56. cardiac muscle is very limited in its
  57. cardiac muscle has what type of fibers? caused by?
    • striated fibers
    • caused by myofibrils made of repeating units
  58. involuntary muscle fiber?
    cardiac muscle
  59. how is cardiac muscle different from striated?
    it doesn't have cells fusing together, meaning the cells are not multinucleated
  60. cells in cardiac muscle are not?
  61. how are cardiac muscle fibers attached?
    from end to end
  62. what is found where cardiac muscle fibers attach at ends?
    intercalated discs
  63. what type of muscle fibers are branched? unbranched?
    • cardiac muscle
    • striated
  64. position of nucleus is centrally located
    cardiac muscle
  65. cardiac muscle fiber contraction?
    • each fiber has one rate of contraction
    • each fiber can contract without any signaling by themselves
  66. rates of cardiac muscle fibers?
    some rates are slow, some are fast _-- they go at their own pace
  67. contraction in cardiac muscle fibers spreads from?
    cell to cell
  68. if cardiac muscle fibers are in a group then?
    they will contract together, they contract at the frequency of the fiber with the quickest rate of contraction
  69. cardiac muscle fiber contraction can also be initated by?
    nervous system, slow down or speed up
  70. specialized fibers for regulating info in the different chambers of heart
    purkinje fibers
  71. purkinje fibers are specialized in?
    coordinating contractions in different chambers of heart
  72. cardiac muscle fibers rate of contraction?
    relatively slow, resistant to fatigue
  73. smallest unit that contracts?
  74. has actin, but lacks myosin
  75. has myosin and actin
    A band
  76. __ ___ stays the same shape, but __ ___ shortens
    • A-band
    • I-Band
  77. ectoderm touches?
    somatic mesoderm
  78. endoderm touches?
    splanchnic mesoderm
  79. amniotic is?
  80. yolk sac is?
  81. order of striated muscle?
    • myofilament
    • myofibril
    • muscle fibers
    • fascicle
    • muscle
  82. order of smooth muscle?
    • lumen
    • mucosa
    • submucosa
    • circular muscle cells
    • longitudinal muscle cells
    • serosa