Term
| 1. Can a motor neuron innervate more than one muscle fiber? |
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Definition
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Term
| 2. What is the term for the highly excitable region of a muscle fiber where a neuromuscular junction is located? |
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Definition
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Term
| 3. What muscle fiber characteristics would you see at the motor end plate? |
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Definition
| hightly folded sarcolemma and lots of mitochondria |
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Term
| 4. What neurotransmitter does the motor neuron release at a neuromuscular junction? |
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Definition
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Term
| 5. Name a drug that inhibits the release of acetylcholine from motor neurons causing muscles to be paralyzed. |
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Definition
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Term
| 6. What does acetylcholine bind to on the motor end plate? |
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Definition
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Term
| 7. What happens when the acetylcholine receptors open (what flows where)? |
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Definition
| sodium flows into the muscle cell |
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Term
| 8. Where will action potentials produced at the motor end plate travel? |
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Definition
| along sarcolemma and down t-tubules |
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Term
| 9. Action potentials that travel down the t-tubules will cause what to open on the terminal cisterna of the sarcoplasmic reticulum? |
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Definition
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Term
| 10. What will the calcium released from the sarcoplasmic reticulum bind to? |
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Definition
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Term
| 11. The conformational change in troponin due to calcium will cause what to happen? |
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Definition
| a conformational change in tropomyocin that will reveal active sites on actin |
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Term
| 12. What are the active sites on actin for? |
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Definition
| where myocin heads bind to actin |
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Term
| 13. What is attached to the myocin head when it is in a high energy state? |
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Definition
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Term
| 14. What is released from the myocin head BEFORE it attaches to the active site on actin? |
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Definition
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Term
| 15. What is released from the myocin head AFTER it attaches to the active site on actin? |
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Definition
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Term
| 16. What is the term for the ratchet like movement of the myocin head that causes the thin filaments to slide over the thick filaments? |
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Definition
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Term
| 17. During a contraction, do sarcomeres shorten or lengthen? |
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Definition
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Term
| 18. What causes the myocin head to release from actin? |
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Definition
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Term
| 19. After muscle contraction, what happens to the calcium? |
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Definition
| it is actively pumped back into the sarcoplasmic reticulum |
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Term
| 20. What happens to the acetylcholine left in the synapse of the neuromuscular junction? |
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Definition
| it is broken down by acetylcholinesterase into acetic acid + choline |
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Term
| 21. What parts of a sarcomere shorten during contraction? |
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Definition
| the whole sarcomere, the I band, and the H zone |
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Term
| 22. What parts of a sarcomere remain the same during contraction? |
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Definition
| the A band and the myofilaments themselves |
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Term
| 23. What sarcomere length allows for the maximum number of cross-bridges and generates the greatest amount of tension? |
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Definition
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Term
| 24. What sarcomere length limits the number of cross-bridges that can be formed (less actin/myosin overlap)? |
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Definition
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Term
| 25. What happens to the tension produced if the sarcomere length is greater than 2.25 um? |
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Definition
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Term
| 26. What sarcomere length limits the distance for the thin filaments to slide? |
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Definition
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Term
| 27. What happens to the tension produced if the sarcomere length is less than 2.0 um? |
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Definition
| the tension generated is reduced |
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Term
| 28. What is the term for a single contraction of a single muscle fiber in response to a single stimulus? |
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Definition
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Term
| 29. During a twitch, what is the term for the time between stimulus and beginning of contraction? |
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Definition
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Term
| 30. During a twitch, what is the term for the time during which contraction occurs? |
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Definition
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Term
| 31. During a twitch, what is the term for the time during which relaxation occurs? |
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Definition
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Term
| 32. Does the magnitude of a single MUSCLE FIBER twitch change if you increase the stimulus strength? |
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Definition
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Term
| 33. During a twitch, what is going on during the lag phase? |
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Definition
| time for the calcium to attach to troponin, troponin to change shape, tropomyocin to change shape, etc. |
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Term
| 34. What are two types of summation for successive MUSCLE FIBER twitches? |
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Definition
| multiple-wave summation and temporal summation |
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Term
| 35. During summation, what happens to the lag phase and relaxation phase? |
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Definition
| they shorten and begin to disappear |
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Term
| 36. During summation, what happens to the contraction phase? |
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Definition
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Term
| 37. During summation, what happens to the tension generated? |
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Definition
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Term
| 38. What is the term for a sustained contraction due to maximal frequency of stimuli? |
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Definition
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Term
| 39. During tetanus, what happens to the lag phase and relaxation phase? |
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Definition
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Term
| 40. During tetanus, what happens to the contraction phase? |
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Definition
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Term
| 41. During tetanus, how much tension is generated? |
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Definition
| the greatest amount of tension (at its peak) |
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Term
| 42. During a twitch of a MUSCLE FIBER, what genertes tension? |
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Definition
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Term
| 43. During a twitch of a WHOLE MUSCLE, what genertes tension? |
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Definition
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Term
| 44. For the muscles in your fingers, are there a few or a lot of muscle fibers per motor unit? |
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Definition
| a few (allows for finer movements) |
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Term
| 45. For the muscles in your legs and back, are there a few or a lot of muscle fibers per motor unit? |
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Definition
| a lot (for larger gross movements) |
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Term
| 46. What are two types of summation for WHOLE MUSCLE twitches? |
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Definition
| multiple motor unit summation and spatial summation |
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Term
| 47. What does a larger stimulus do during multiple motor unit summation? |
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Definition
| more motor units are recruited |
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Term
| 48. What happens to the tension generated during multiple motor unit summation? |
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Definition
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Term
| 49. If you have stimulated the maximum number of motor units for a given muscle and get x amount of tension produced, what will happen if you increase the stimulus? |
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Definition
| you will still produce the same amount of tension because you have already reached the maximum amount of motor units |
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Term
| 50. What type of muscle contraction will change muscle length? |
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Definition
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Term
| 51. What type of muscle contraction will not change muscle length? |
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Definition
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Term
| 52. What is the term for the isotonic contraction where muscle tension exceeds resistance and the muscle shortens? |
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Definition
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Term
| 53. What is the term for the isotonic contraction where resistance exceeds muscle tension and the muscle lengthens? |
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Definition
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Term
| 54. If I am pushing against a wall, what type of muscle contraction is occuring? |
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Definition
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Term
| 55. What is the state of partial muscle contraction due to nerves continually stimulating motor units? |
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Definition
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Term
| 56. What happens to muscle tone with upper motor neuron damage? |
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Definition
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Term
| 57. What happens to muscle tone with lower motor neuron damage? |
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Definition
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Term
| 58. What is the term for the involuntary and forcible contracture of muscle with failure to relax? |
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Definition
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Term
| 59. What are three common causes for muscle cramps? |
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Definition
| fatigue / low EXTRACELLULAR calcium / dehydration |
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Term
| 60. What is the state of constant muscle rigidity that occurs several hours after death? |
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Definition
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Term
| 61. Rigor mortis occurs because of a complete depletion of ATP - what does this not allow? |
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Definition
| does not allow the myosin heads to release from actin |
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Term
| 62. What is the immediate source of energy for a muscle contraction (provides only few seconds of energy) |
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Definition
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Term
| 63. What are four other sources of energy for muscle contraction? |
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Definition
| phosphocreatine, glycogen (glucose), fat (fatty acids & glycerol), and protein (amino acids) |
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Term
| 64. What type of energy is preferentially utilized during low to moderate intensity exercise? |
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Definition
| fat (fatty acids/glycerol) |
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Term
| 65. What type of energy is preferentially utilized during moderate to high intensity exercise? |
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Definition
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Term
| 66. What type of energy is utilized when glycogen and fats are depleted? |
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Definition
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Term
| 67. What process is a direct phosphorylation of ATP to yield 10 to 15 seconds of energy? |
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Definition
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Term
| 68. What process is a rapid production of ATP, does not require oxygen, and provides about 90 seconds of energy? |
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Definition
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Term
| 69. What process occurs during prolonged activity and yields 32 ATP per glucose molecule? |
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Definition
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Term
| 70. What is the sole source of energy used in anaerobic metabolism and what is this process called? |
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Definition
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Term
| 71. What is produced as a waste product of glycolysis? |
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Definition
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Term
| 72. What can be used as a source of energy in aerobic metabolism? |
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Definition
| glucose, fatty acids, or amino acids |
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Term
| 73. What type of muscle fatigue may be linked to interleukin 6 that signals the brain to feel tired as a defense mechanism to conserve energy? |
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Definition
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Term
| 74. What type of fatigue is due to a depletion of energy sources and an inefficiency to deliver oxygen? |
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Definition
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Term
| 75. What three things are accumulated (and where) during muscular fatigue? |
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Definition
| potassium (outside muscle fiber), phosphate (inside muscle fiber), and lactic acid (due to anaerobic metabolism) |
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Term
| 76. What type of fatigue is due to defective acetylcholine receptors or a decreased amount of acetylcholine released at the neuromuscular junction? |
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Definition
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Term
| 77. What is an example of an autoimmune destruction of acetylcholine receptors? |
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Definition
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Term
| 78. What is an example of an autoimmune destruction of pre-synaptic calcium channels? |
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Definition
| Lambert-Eaton myasthenia syndrome |
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Term
| 79. What type of muscle fiber has a high respiratory capacity, high concentration of mitochondria, and a high concentration of myoglobin? |
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Definition
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Term
| 80. What type of muscle fiber has a high concentration of glycogen and a very low concentration of myoglobin? |
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Definition
| white, fast twitch fibers |
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Term
| 81. What type of muscle fibers are slow oxidative fibers? |
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Definition
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Term
| 82. What type of muscle fibers are fast glycolytic fibers? |
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Definition
| white, fast twitch fibers |
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Term
| 83. What type of muscle fibers are suited for endurance and contract slowly (slow myosin)? |
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Definition
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Term
| 84. What type of muscle fibers are suited for power movements and contract rapidly (fast myosin)? |
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Definition
| white, fast twitch fibers |
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Term
| 85. What does slow and fast myosin mean? |
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Definition
| slow - they hydrolyze ATP slowly / fast - they hydrolyze ATP fast (time it takes to start a new cross-bridge) |
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Term
| 86. What type of muscle fiber is a type I fiber? |
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Definition
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Term
| 87. What type of muscle fiber is a type IIb or type IIx fiber? |
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Definition
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Term
| 88. What type of muscle fiber is a fast twitch fiber and fatigue resistant? |
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Definition
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Term
| 89. What type of muscle fiber is a fast oxidative-glycolytic fiber? |
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Definition
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Term
| 90. What type of muscle fiber is type IIa or type III fibers? |
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Definition
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Term
| 91. How do muscle cells grow? |
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Definition
| by hypertrophy (enlargement) not hyperplasia (cell division) |
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Term
| 92. What is the protein that prevents hyperplasia in muscle cells? |
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Definition
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Term
| 93. What type of muscle lines the walls of internal organs and is involuntary? |
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Definition
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Term
| 94. What type of smooth muscle arrangement is sheets of spindle shaped cells that function together? |
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Definition
| single-unit/visceral smooth muscle |
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Term
| 95. What type of smooth muscle arrangement is less organized and cells function independently of one another? |
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Definition
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Term
| 96. Where would you find single-unit smooth muscle? |
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Definition
| walls of digestive tract, ureters, and uterus |
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Term
| 97. Where would you find multiunit smooth muscle? |
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Definition
| arector pili muscle, in the iris, and walls of some blood vessels |
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Term
| 98. In smooth muscle, how are myofibrils organized (striated or not)? |
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Definition
| organized randomly (not striated) |
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Term
| 99. In smooth muscle, what anchors actin to the sarcolemma? |
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Definition
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Term
| 100. In smooth muscle, what anchors actin to the sarcoplasm? |
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Definition
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Term
| 101. What two things are lacking in smooth muscle? |
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Definition
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Term
| 102. What is the calcium binding protein in smooth muscle (instead of troponin)? |
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Definition
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Term
| 103. During excitation of smooth muscle, where does most of the calcium come from (remember - in skeletal from SR)? |
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Definition
| mostly from extracellular stores (little from SR) |
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Term
| 104. In smooth muscle, what is activated once the calcium binds to calmodulin? |
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Definition
| myosin kinase (it phosphorylates myosin head to put it in active state) |
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Term
| 105. In smooth muscle, the calcium-colmodulin complex does not cause the conformational change in tropomyosin (like troponin), what protein on actin actually does this? |
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Definition
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Term
| 106. In smooth muscle, are contraction slow or fast, and why? |
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Definition
| slow because the enzymes involved in cross-bridging are slow |
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Term
| 107. In smooth muscle, once the calcium is pumped out of the cell, what will the low concentration of calcium activate that will dephoshporylate the myosin head and cause relaxation? |
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Definition
| myosin phosphatase (in skeletal - ATP) |
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Term
| 108. Can smooth muscle contractions be graded and sustained? |
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Definition
| yes, can be graded (remember - not skeletal) and sustained |
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Term
| 109. What is the term for the sustained contraction of smooth muscle? |
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Definition
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Term
| 110. Is cardiac muscle voluntary/involuntary, and striated/nonstriated? |
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Definition
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Term
| 111. In skeletal muscle, the t-tubules are located between the A-band and the I-band, where are the t-tubules located in cardiac muscle? |
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Definition
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Term
| 112. In skeletal muscle, the t-tubules formed triads with the terminal cisterna, what is formed with the t-tubules in cardiac muscle? |
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Definition
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Term
| 113. In cardiac muscle, stimulation of the sarcolemma will cause what _____ , that will in turn stimulate the release of calcium from the SR? |
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Definition
| the influx of calcium into the sarcoplasm (calcium-induced calcium release) |
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Term
| 114. What is located between cardiac muscle cells that allow these cells to contract at the same time and help them form a syncitium? |
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Definition
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