1. Which of the following protein(s) is/are found in thin filaments? (check all that apply) (0.25pts)

    • tropomyosin
    • troponin
    • actin
  2. One nerve fiber and all the muscle fibers innervated by it are a: (0.25pts)

    contractile unit
    motor unit
    motor unit
  3. The contractile unit of a muscle fiber is the: (0.25pts)

    motor unit
  4. Which of the following is a neurotransmitter that fills synaptic vesicles and is used to signal between the nerve and muscle? (0.25pts)

    oxaloacetic acid
  5. Which type of muscle contraction produces a change in muscle tension but no change in muscle length? (0.25pts)

  6. Fast glycolytic muscle fibers have which of the following characteristics? (check all that apply) (0.5pts)

    anaerobic ATP synthesis
    slow ATP hydrolysis
    high myoglobin content
    poor fatigue resistance
    few capillaries making the tissue white in color
    many large mitochondria
    • poor fatigue resistance
    • few capillaries making the tissue white in color
  7. Which of the following causes muscle fatigue? (check all that apply) (0.5pts)

    lactic acid inhibits protein function
    motor nerve fibers use up all the Ca2+ in the ECF
    less ATP synthesis
    accumulation of Na+ ions in the ECF
    less signal input to the muscle by the central nervous system
    • lactic acid inhibits protein function
    • less ATP synthesis
    • less signal input to the muscle by the central nervous system
  8. In smooth muscle, the calcium for contraction comes mainly from: (0.5pts)

    dense bodies
    sarcoplasmic reticulum
    extracellular fluid
    extracellular fluid
  9. In muscle metabolism, the phosphagen system is used for: (0.25pts)

    Repayment of oxygen debt
    Long-term energy (for prolonged exercise)
    Immediate energy (the first 10 seconds of intense exercise)
    Short-term energy (the first 1 minute of intense exercise)
    Immediate energy ( the first 10 seconds of intense exercise)
  10. The plasma membrane in the muscle fiber is referred to as:
  11. the protein filled cytoplasm of the muscle fibers is referred to as:
  12. The contractile proteins in a muscle fiber that are organized into enlongated bundles are referred to as:
  13. the verticle plate of proteins that supports the thin filaments is known as:
    Z discs
  14. the portion of the myofibril located between the two z discs is known as:
  15. the ______ is a reservoir of calcium ions; it has gated channels in its membrane that open at the right times to release a flood of calcium into the cytostol.
    scaroplasmic reticulum
  16. the plasma membrane of a msucle fiber is called its ______ and its cytoplasm is called its _____.
    • sarcolemma
    • sacroplasm
  17. List the three things that are contained in the sarcoplasm:
    • myofibrils
    • glycogen: carbohydrate provides energy
    • myoglobin: stores oxygen for muscle activity
  18. the sarcolemma has tubular infoldings called ___, which penetrate through the cell from one side to the other.

    what is its fxn?
    • T tubules (transverse)
    • Fxn: signals the SR when to release calcium bursts
  19. The protein found in thick filaments is called:
  20. The thick filaments are ____ in the sarcromeres, while the thin filaments ___ in and out towards the z line
    • stationary
    • move
  21. True/False: Myofilaments are arragned into sacromeres.
    False: myofibrils are arragned into sacromeres
  22. True/False: A muscle cell can also be referred to as a muscle cell.
  23. the proteins found in thin filaments are called:
  24. when a muscle fiber is relaxed, each ____ blocks the binding sites on actin and prevents myosin from binding to them.
  25. the protein of a thin filament that covers actin is called:
  26. List the three components of thin filaments:
    • actin
    • tropomyosin
    • troponin
  27. Dark bands formed by parallel thick filaments that partly overlap the thin filaments is called the
    A band ( think "dArk")
  28. A lighter region in the middle of an A band that contains thick filaments only; thin filaments do not reach this far into the A band in relaxed msucle is called:
    H band
  29. A dark line in the middle of an H band, where thick filaments are linked is called:
    M line
  30. A light band composed of thin filaments only is called:
    I Band (think lIght)
  31. A protein disc to wich thin fialments and elastic filaments are anchored at each end of a sarcomere is called
    the Z disc
  32. The distance from one Z disc to the next; the contractile unit of a muscle fiber is called:
  33. In terms of skeletal muscle organization, _____ are made up of myofilaments which form a ____ ____ , which then makes up a Fasicle which combind to make a __________.
    • myofibrils
    • muscle fiber
    • msucle group
  34. What is the fxn of Smooth ER in a muscle?
    • used to store Ca2+
    • contraction
  35. What is the repeating fxnal unit of a muscle tissue called?
  36. During a muscle contraction, the _____ shortens by pulling the _____ closer together.
    • sacromere
    • z disc
  37. One nerve fiber and all the msucle fibers innervated by it is called:
    motor unit.
  38. Describe the # of fibers, location, and fxn of a small motor unit:
    • # of fibers: 3 - 6 fibers
    • Location: fingers, eyes
    • Fxn: Fine motor control
  39. Describe the # of fibers, location, and fxn of a large motor unit:
    • # of fibers: 1000 muscle fibers
    • fxn: strength
    • location: gluteal or quadricep muscles
  40. What are the fxn of motor units:
    • Strength
    • control
    • work in shifts/sustain long term contraction
  41. Describe the structure of a motor unit:
    • Image Upload 1
    • cell bodies are in the brainstem/spinal cord
    • axons (somatic motor fibers) lead to skeletal muscles
    • each single nerve fiber branches out to a number of muscle fibers
    • terminal branches spreads out and stiumulates all msucle fibers supplied by the nerve fiber
    • muscle fibers of a single motor unit are not clustered together, but dispersed throught a muscle.
  42. Image Upload 2
    Lable the sacrolemma, snyaptic knbo, snyaptic cleft, snyaptic vesicles, junctional folds
  43. the _____ of NMJ is irregualry indented, a little like a handprint pressed into soft clay, outside the synaptic cleft is called:
  44. the nerve fiber ends in a bulbous swelling, where action potential is discharged is called the:
    synapitc knob
  45. the knob doesnt directly touch the muscle fiber but is separated from it by a narrow space called:
    synaptic cleft
  46. the synaptic knob contains spheroidal organelles _______ which contain ACh
    synaptic vesicles
  47. to respond to ACh the mucles fiber has about 50 million ______ that occur directly across from the synaptic knobs.
    ACh receptors
  48. to maximize the # of ACh receptors and the sensitivity to the ACh the sarcolemma has ________ which increase the surface area of teh ACh senesitive membrane.
    junctional folds
  49. Explain the role of the synaptic vesicels:
    the electrical signal ( nerve impulse) cannot jump across the synaptic cleft like a spark, so the nerve impulse casues the snypatic vesicles to undergo exocytosis, releasing ACh into the cleft.
  50. Describe the role of ACh:
    to excite the muscle fibers
  51. Describe the role of the ACh receptors:
    connection between the neuron and the muscle
  52. Describe the role of the Acetylcholinesterase:

    Why is it important?
    the enzyme breaks down ACh after the ACh has stimulated the muscle

    important: turns off muscle contraction, allows it to relax
  53. List three types of flaccid paralysis:
    • Botulism
    • Myasthenia gravis
    • Curare
  54. the state in which muscles are limp and cannot contract is called:
    flaccid paralysis
  55. one cause of flaccid paralysis, considered a poison in which competes with ACh for receptors but does not stimulate the muscle is called:
  56. the cause of flaccid paralysis in which ACh release is blocked is called:
  57. the cause of flaccid paralysis that is a result in an autoimmune disorder, in which there is a defiecency of ACh receptors is called:
    myasthenia gravis
  58. a state in which muscles contract and cannot relax is called:
    spactic paralysis
  59. List two examples of spastic paralysis:
    • sarin nerve gas
    • rigor mortis
  60. Described the polarized plasma membrane in a cell at rest
    • ECF: excess of Na+ ions, electropositive
    • ICF: excess of K+, and anions of proteins, nucleic acids, and phosphates making it more electronegative
  61. the separation of charge between the ECF and the ICF in the sarcolemma establishes the:
    Resting membrane potentional (RMP)
  62. The RMP of a muscle cells is:
    -90 mv (millivolts)
  63. the ion channels in the plasms membrane of an excited muscle opens and Na+ diffused down the concentration gradient, so that the inside of the cell is slightly postive is known as:
  64. Immediately when the ICF becomes slightly positive the Na+ channels close and open K+ channels and the K+ rushs out turing the ICF back to slightly negative again is called:
  65. the quick voltage shift from negative RMP to a postive value and then back down again is called:
    action potential
  66. Describe the importance of action potential:
    it is the point in which Ca2+ is release, and the muscle contracts
  67. Outline the sequence of events in muscle contraction:
    • 1. action potential generate by the nerve travels down the t tubels, electrical potentional acts on the SR and releases Ca2+ into the cytostol
    • 2. Ca2+ binds to troponin, causes troponin to change shape, which pulls troypomyosin, exposing myosin binding sites
    • 3. myosin binds to the binding sites, this causes ADP, P to leave the myosin head, and causes the myosin to move and pull actin towards the sacromere
    • 4. a new ATP attaches to the mysoin head, causing it to detach from actin, the ATP hydrolizaes into ADP, P and is ready to start the cyle again.
  68. Outline the sequence of events in muscle relaxation:
    • 1. myosin must first detach from actin, happens when ATP attaches to myosin to break the cross brigde.
    • 2. nerve impusles stop, ACh is broken down by AChE
    • 3. Ca2+ leaves the troponin, and is absorbed back into the SR via active transport ( requires ATP)
    • 4. causes troypomyosin to curl around on the binding sites
  69. Describe the role of Ca2+ in muscle relaxation:
    Ca2+ leaves the troponin, absorbed back into the SR via active transport ( requires ATP) and causes the tropomyosin to cover the binding sites again
  70. Describe the three roles of ATP in muscles:
    • 1. Break cross bridges - between myosin and actin
    • 2. Active transport - to get Ca2+ back into the SR, and to depolarization by the NA+ K+ pump
    • 3. Muscle Metabolism
  71. Define Rigor Mortis:

    Explain the causes:
    Definition: harding of muscles and stiffening of the body 3 - 4 hours after death

    Causes: deterioration SR releases Ca2+, Ca2+ activates myosin-actin cross bridges, myosin can't release w/o ATP and no ATP is available in a dead body
  72. Describe the role of ATP in Rigor Mortis:
    myosin cant release from the myosin-actin cross bridge w/o ATP, and no more ATP is available in a dead body
  73. What are the three ways to vary muscle tension?
    • Motor unit recruitment
    • length-tension relationship
    • temporal summination
  74. Explain what happens during each phase of a muscle twitch:
    • latent period: delay of about 2 millseconds b/w onset of stimulis and the onset of the twitch
    • contraction phase: the muscle begins to produce external tension and move a resisting object or load, short - lived
    • relaxation phase: SR quickly reabsorbs Ca2+ before muscle develops maximal force, ca2+ leaves, myosin releases, tension declines
  75. Describe what factors vary the strength of a muscle twitch:
    • frequency in which stiumlation takes place: closer together - stronger
    • the Ca2+ concentration in the sarcoplasm
    • how stretched the muscle was before situmation took place
    • Temp, pH, and Hydration
  76. Describe how the length - tension relationship determines the strength of muscle contraction:
    • overly contracted: thick filaments butt against the Z disc and the muscle fiber cant contract much more
    • overly stretched: too little overlap b/w the thick and thin myofilaments that few cross-bridges are made
    • ideal: max # of cross bridges can be made
  77. True/False: all muscle contractions are considered all or nothing - the # of nerve firings has no impact on the strength of the contraction
    False - the # of firings does have impact on strenght of contraction and are considered all or nothing
  78. Describe motor unit recruitment:
    • Subthreshold stimuli: produces no muscle contraction
    • threshold and above: excites more and more nerve fibers and motor units, stronger contractions
    • maximum: all nerve fibers are stimulated, no further increase in muscle tension
  79. Describe the effect of temoral summation:
    • Each new stimulus arrives before the previous twitch is over, generates higher tension, and the muscle relaxes only partially between stimuli
    • Treppe: moderate freq. of stimulation, muscle relaxes fully b/w contractions
    • Incomplete teanus: higher freq., muscle does not have time to relax between contraction twitchs
    • Complete teanus: high freq., muscle does not have time to relax at all, continual contraction, muscle fatigues, tension declines
  80. Describe the contracted sacromere:
    • Z line: moves in
    • A band: does not move
    • I band: shortens (actin is pulled)
    • H band: reduced in space
  81. a contraction in which there is a change in tension, without change in length is called:

    • "iso" - same
    • "metric"- measure, length

    Example: Holding a weight, muscle devlopes tension, but doesnt change length
  82. a contraction in which there is a change in length at constant tension is called:

    • "iso" same
    • t - tonic - tension
  83. muscle shortening is known as:
    • concentric contraction
    • Ex: Flexing your arm to bring a weight up
  84. muscle lengthening is known as:
    • eccentric contraction:
    • Ex: extending your arm down to bring down a weight during a bicep curl
  85. Describe how muscle get ATP for immediate energy, the phosphage system:

    List the 2 enzymes involved:
    a. gets most of its ATP needs from borrowing phosphate groups from other molecules and transfering them to ADP

    Enzymes: myokinase, Creatine(not a standard source)

    **buying time until other systems kick in**
  86. Describe how muscles get ATP for short term energy, anaerobic fermenation, and glycolysis:
    • glycolysis: break down glucose, generating ATP, glucose is converted to lactic acid
    • anaerobic (no oxygen): lactic acid builds up, crystals

    *doesnt last long, still buying time until long term energy*
  87. Describe how mucles get ATP for long term energy from aerobic respiration:
    Glycogen is broken down (2 atp) into pyruvic acid, Pyruvid acid goes into citric acid cycle, then finally the electron transport chain for 36 ATP.

    glucose comes from glycogen and fatty acids
  88. State factors that contribute to muscle fatiuge:
    • No more glycogen ( fuel depletion)
    • latic acid build up - more acidic, enzymes dont work as effiecently
    • K+ in ECF builds up - no xchange of Na+ and K+ is less exictiability of fibers
    • ADP, P accumilation
    • Electrolyte loss
    • Central nervous system fatigue - mental fatigue
    • ACh deficit - decrease excitablilty
  89. List the three modes of ATP systhesis in msucle metabolism:
    • Immediate Energy: phosphagen system
    • Short term Energy: glycogen-lactic acid system (glycolysis, anaerobic ferementation)
    • Long term: aerobic respiration
  90. Compare Slow oxidative and Fast glycolytic fibers:
    • Slow
    • ATP: aerobic
    • Myoglobin: abundant
    • glyocgen: low
    • mitochondria: abundant and large
    • capillaries: abundant
    • color red

    • Fast
    • ATP: anaerobic
    • Myoglobin: low
    • glycogen: abundant
    • mitochondria: few and small
    • capillaries: few
    • color: white
  91. List three ways in which smooth muscle is similar to skeletal muscle:
    • 1. filaments slide
    • 2. Ca2+ for contractions
    • 3. use ATP
  92. Liste the cellular structure, location, source of stimulation, source of calcium and level of control of smooth muscle:
    • Smooth
    • cellular structure: single nucli, no striations, no sacromere, no t tubules, no troponin
    • location: lines hollow organs, intestines, lungs, piloerector
    • source of stimiulation: autonomic nervous system, how acidic, stretch, and pace maker activity
    • level of control: involuntary
    • source of calcium: ECF
  93. which type of energy ( muscle metabolism) would you use to for a few yards chase after a soccer ball? _____ or _____
    immediate or short term
  94. which is NOT a cause of muscle fatigue?

  95. which of the following is NOT a mode of sitmulating smooth muscle?

  96. in a slow wocidative muscle how abundant are the following substances:
    • glycogen: low
    • capillaries: abundant
    • myoglobin: abundant
  97. which of the following is not a fxn of muscle tissue:

  98. what is the opposing force of an isometric contraction?

  99. the sacromere is the repeating ____ __
    __ of the myofibril and has the organizational order
    a. zaihiaz
    b. izhahzi
    c. ziahaiz
    d. haiziah
    • functional unit
    • c
  100. which of the terms refers to a "muscle cell"

  101. which part of actin does calcium bind to to uncover tropomyosin from the myosin binding sites?
    a. myosin heads
    b. troponin
    c. distal troyomyosin
    d. thin filament
    e. synaptic vesicles
  102. true/false: each muscle is innervated by many neurons
  103. true/false: during a msucle contraction the distance between the z discs and the h band both shorten
  104. true/fasle: one muscle fiber action potential causes only one muscle fiber twitch
Card Set
muscle tissue