Understanding Muscle Contraction and Nervous System Functions

Posted on Feb 10, 2024 in Biology

CHAPTER 9

  1. What is the role of calcium ions in the contraction of skeletal muscle?

    1. Calcium ions bind to the troponin-tropomyosin

  2. The functional unit of a skeletal muscle fiber is the ______.

    1. Sarcomere

  3. Interactions between thin and thick myofilaments of the sacromere are responsible for ________.

    1. Muscle contraction

  4. During muscle contraction, all of the following occur EXCEPT ______.

    1. Calcium concentrations in the sarcoplasm decrease

  5. During a muscle contraction, muscle fibers shorten when ______.

    1. Thin myofilaments are pulled toward the center of the sarcomere by the pivoting of the myosin heads

  6. The elaborate network of membranes in skeletal muscle cells that functions in calcium storage is the ______.

    1. Sarcoplasmic reticulum

  7. What is the function of T tubules?

    1. They conduct action potentials from the sarcolemma to the interior of the muscle cell

  8. One transverse tubule plus two adjacent terminal cisternae form a _____.

    1. Triad

  9. Which links excitation to contraction in a skeletal muscle fiber?

    1. Calcium

  10. As action potentials travel down a T tubule, a voltage-sensitive protein changes shape. This shape change opens a ________.

    1. Calcium release channel

  11. The portion of the sarcolemma in contact with the axon terminals is called the _____.

    1. Motor end plate

  12. At the neuromuscular junction, calcium ions act to _______.

    1. Release synaptic vesicles from the axon terminal

  13. The first thing that occurs when the axon terminal releases ACh is ________.

    1. Diffusion of ACh across the synaptic cleft

  14. What type of ion channel opens in response to an action potential arriving at the axon terminal?

    1. Voltage- gated calcium

  15. What is the name of the enzyme that degrades ACh?

    1. Acetylcholinesterase

  16. Of the following muscle types, which is the only one subject to conscious control?

    1. Skeletal

  17. Which of the following muscular functions serves a metabolic function?

    1. Heat generation

  18. In order to receive a signal to contract, each skeletal muscle must be served by a(n) ______.

    1. Nerve

  19. Which of the following components accounts for the bulk of muscle fiber volume (up to 80%)?

    1. Myofibrils

  20. The thin filaments are not comprised of which of the following components?

    1. Titin

  21. What is the significance of the muscle fiber triad relationship?

    1. The tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum

  22. During a muscle contraction, the sliding filament theory would be apparent in a sarcomere because ______.

    1. The H zone becomes less obvious and the Z discs move closer together

  23. At the neuromuscular junction, the muscle contraction initiation event is ______.

    1. Binding of acetylcholine to membrane receptors on the sarcolemma

  24. In a muscle fiber, the key intracellular event that stimulates muscle contraction is known as ______.

    1. Depolarization

  25. During depolarization, the sarcolemma is most permeable to _____.

    1. Sodium ions

  26. What is calcium’s function during muscle contraction?

    1. Calcium binds to troponin, changing its shape and removing the blocking action of tropomyosin

  27. Small precise movements are controlled by _____ motor units

    1. Small

  28. A sprinter is likely to depend on ______ respiration to generate ATP, and a Tour de France cyclist is likely to rely on _____ respiration.

    1. Anaerobic; aerobic

  29. Sprinters typically possess more ______ muscle fibers.

    1. Fast oxidative

  30. A major difference between smooth muscle fibers and skeletal muscle fibers in terms of calcium influx is that _____.

    1. Calcium ion influx occurs mostly from the extracellular fluid in smooth muscle

  31. A major cellular feature in smooth muscle that contributes to its rhythmicity and ability to participate in peristalsis is the presence of _____.

    1. Gap junctions

  32. The principal neurotransmitter of skeletal muscle is acetylcholine. The major neurotransmitter of smooth muscle is ______.

    1. Acetylcholine, epinephrine, norepinephrine

  33. Electrical coupling by gap junctions is present in ______.

    1. Unitary smooth muscle

CHAPTER 10

  1. The muscle that provides the major force producing a specific movement is a _____.

    1. Prime mover

  2. You could conclude that a muscle with the term “rectus” included in its name is a muscle whose fibers run ____ to the body’s vertical axis

    1. Parallel

  3. Flexing the forearm with the biceps brachii is an example of which class of lever system?

    1. Third class

  4. When you bite down, this muscle strongly contract.

    1. Masseter

  5. When you lie on your back, your ______ muscles contract to lift your head.

    1. Sternocleidomastoid

  6. The muscles of the ______ are rather unusual for muscles because they insert onto the skin or other muscles.

    1. Face

  7. The _____ is/are the most important muscle for inspiratory breathing

    1. Diaphragm

  8. The levator ani and _____ muscles form the pelvic diaphragm.

    1. Coccygeus

  9. The ______ muscles include the supraspinatus, infraspinatus, teres minor, and subscapularis

    1. Rotator cuff

  10. Swimmers tend to have particularly well-developed ______ muscles.

    1. Latissimus dorsi

  11. The ____ muscle is the most powerful muscle in the body.

    1. Quadriceps femoris

  12. The _____ muscle comprise the triceps surae that inserts onto the calcaneal tendon and are prime movers of plantar flexion.

    1. Gastrocnemius and soleus

CHAPTER 11

  1. Information gathered by sensory receptors about internal and external changes

  2. Processing and interpretation of sensory input

  3. Activation of effector organs which produces a response

  4. What are the effector organs?

  5. muscles and glands

  6. What is comprised of the brain and spinal cord, and is the integration and control center?

  7. central nervous system

  8. What system interprets sensory input and dictates motor output

  9. central nervous system

  10. What portion of the nervous system consists mainly of nerves?

  11. peripheral nervous system

  12. What types of nerves make up the PNS?

  13. spinal and cranial

  14. How many pairs of spinal nerves are in the PNS?

  15. 31

  16. How many cranial nerves are in the PNS?

  17. 12

  18. What are the function divisions of the PNS?

  19. sensory and motor

  20. Which division of the PNS is afferent?

  21. sensory

  22. Which division of the PNS is efferent?

  23. motor

  24. Which fibers in the PNS sensory (afferent) division convey impulses from skin, skeletal muscles, and joints to the CNS?

  25. somatic sensory fibers

  26. What fibers in the PNS sensory (afferent) division convey impulses from visceral organs to CNS?

  27. visceral sensory fibers

  28. What division of the PNS receives and sends towards the CNS?

  29. afferent

  30. Which division of the PNS moves from the CNS to muscles or glands?

  31. efferent

  32. Which division of the PNS transmit impulses from the CNS to muscles and glands?

  33. efferent/motor

  34. What are the divisions of the motor (efferent) division of the PNS?

  35. somatic nervous system and autonomic nervous system

  36. Which motor division of the PNS conducts impulses from CNS to skeletal muscles?

  37. somatic nervous system

  38. Which motor division of the PNS has visceral motor nerve fibers and regulates smooth muscle, cardiac muscle, and glands?

  39. autonomic nervous system

  40. What are the functional subdivisions of the autonomic nervous system?

  41. sympathetic and parasympathetic

  42. What is the fight or flight subdivision of the autonomic nervous system?

  43. sympathetic

  44. What is the rest and repose division of the autonomic nervous system?

  45. parasympathetic

  46. What are the main cell types in nervous tissue?

  47. neuroglia and neurons (nerve cells)

  48. What are the small cells in nervous tissue that surround and wrap delicate neurons?

  49. neuroglia

  50. What are excitable cells in nervous tissue that transmit electrical signals

  51. neurons (nerve cells)

  52. Which neuroglia pulls capillaries into the neuron to feed it, providing nutrition and oxygen, and gets rid of waste?

  53. astrocytes

  54. Which neuroglia protects the neuron – can transform to phagocytize micoorganisms and debris?

  55. microglial cells

  56. Which neuroglia range in shape from columnar to squamous, may be ciliated, and synthesize cerebrospinal fluid?

  57. ependymal cells

  58. Which neuroglia are branched cells that mylenate axons – wraps the axon with a myelin sheath?

  59. oligodendrocytes

  60. Which cells found in the PNS function similar to astrocytes by surrounding neuron cell bodies?

  61. satellite cells

  62. Which cells in the PNS are similar to oligodendrocytes by surrounding the nerve fibers and forming myelin sheaths?

  63. Schwann cells

  64. What helps improve and increase the speed of the electrical impulse along the axon?

  65. myelin sheaths

  66. What are the structural units of the nervous system; large specialized cells that conduct impulses?

  67. neurons

  68. What part of the neuron is the center – synthesizes proteins, membranes and other chemicals – integrates and interprets messages?

  69. Neuron cell body (Perikaryon or Soma)

  70. What are clusters of neuron cell bodies in the CNS?

  71. nuclei

  72. What lie along nerves in the PNS?

  73. ganglia

  74. What are armlike processes that extend from the neuron cell body?

  75. neuron processes

  76. What are bundles of neuron processes (axons) in the CNS?

  77. tracts

  78. What are bundles of neuron processes (axons) in PNS?

  79. nerves

  80. What are the types of neuron processes?

  81. dendrites and axons

  82. What neuron process in motor neurons collects information, and is the receptive region of the neuron?

  83. dendrites

  84. One axon per cell arises from the what?

  85. axon hillock

  86. What are the distal endings of the axon called?

  87. axon terminals

  88. What is the neuron cell membrane?

  89. axolemma

  90. What type of movement along the axon travels away from the cell body? (such as mitochondria, enzymes, membrane components)

  91. anterograde

  92. What type of movement along the axon goes toward the cell body? (such as viruses, signal molecules, bacterial toxins)

  93. retrograde

  94. What is the white-ish, protein-lipoid substance?

  95. myelin

  96. What are the functions of myelin?

  97. protects and electrically insulates the axon, increases the speed of nerve impulse transmission

  98. Myelination in the PNS is formed by what?

  99. Schwann cells

  100. What are the regions of the brain and spinal cord with dense collections of myelinated fibers?

  101. white matter

  102. What is mostly neuron cell bodies and nonmyelinated fibers

  103. gray matter

  104. What are the structural classifications of neurons?

  105. multipolar, bipolar, unipolar

  106. What are the functional classifications of neurons?

  107. sensory, motor, interneurons

  108. Which functional classification of neurons transmit impulses toward the CNS, and are almost all unipolar?

  109. sensory

  110. Which functional classification of neurons carry impulses from the CNS to muscles and glands, and are multipolar?

  111. motor

  112. Which functional classification of neurons shuttle signals through CNS pathways, lie between other neurons, comprise 99% of the body’s neurons and are most confined in the CNS?

  113. interneurons

  114. What is a measure of potential energy generated by a separated charge?

  115. voltage

  116. What is the flow of electrical charge (ions) between two points?

  117. current

  118. What is the hindrance to charge flow?

  119. resistance

  120. What is the substance with high electrical resistance?

  121. insulator

  122. What is the substance with low electrical resistance?

  123. conductor

  124. What are the types of ion channels?

  125. leakage (non gated) and gated

  126. Which type of channel is always open?

  127. leakage (nongated)

  128. What type of channel involves part of the protein

    changing shape to open/close the channel?

    gated

    67

    Which type of gated channel open with binding of a specific neurotransmitter?

    chemically gated

    68

    Which type of gated channel opens and closes in response to changes in membrane potential?

    voltage gated

    69

    Which type of gated channel opens and closes in response to physical deformation of receptors (like sensory receptors)?

    mechanically gated channels

    70

    What is the potential difference across the membrane of a resting cell?

    resting membrane potential

    71

    Is the resting membrane polarized or depolarized?

    polarized

    72

    The cell is ________ when more sodium is outside and more potassium is inside.

    polarized

    73

    What is the decrease in membrane potential, wherein the inside of the membrane becomes less negative, and the probability of producing a nerve impulse increases?

    depolarization

    74

    What is an increase in membrane potential, wherein the inside of the cell is more negative, and the probability of producing a nerve impulse is reduced?

    hyperpolarization

    75

    For an axon to “fire” depolarization must reach what?

    threshold

    76

    What is the voltage at which the action potential is triggered?

    threshold

    77

    What is the fact that an AP either happens completely, or it doesn’t happen at all?

    all or none phenomenon


    ere!