Smooth Muscle Physiology - Block 3

36 Questions | Total Attempts: 130

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Muscle Physiology Quizzes & Trivia

Questions and Answers
  • 1. 
    Smooth muscles are found in the
    • A. 

      Lining of hollow organs

    • B. 

      Regulation blood flow

    • C. 

      Digestion tract

    • D. 

      All the above

  • 2. 
    In ______________ smooth muscle, a spontaneous electrical impulses spread through gap junctions.  When one cell receives an action potential all cells will contract.
    • A. 

      Multi unit

    • B. 

      Single unit

    • C. 

      Nucleus

    • D. 

      Golgi

  • 3. 
    Mutli unit smooth muscle are not electtically connected and each cell must receive input.  Multi unit smooth muscle are found in lung airways, large blood vessels, eye muscles and hair follicles.
    • A. 

      True

    • B. 

      False

  • 4. 
    Multiple imputs collectively excite or inhibits smooth muscle leading to action potential is
    • A. 

      Hormones

    • B. 

      Nitric oxide

    • C. 

      Pacemaker cells

    • D. 

      Stretching

    • E. 

      All of the above

  • 5. 
    Neurotransmitters and hormones can excite or inhibit smooth muscle.
    • A. 

      True

    • B. 

      False

  • 6. 
    In smooth muscles, stretching opens mechansensitive ion channels that leads to membrane depolarization.
    • A. 

      True

    • B. 

      False

  • 7. 
    Spontaneous electrical activity in the plasma membrane of the muscle cell is a characteristic of
    • A. 

      Hormones

    • B. 

      Pacemaker cells

    • C. 

      Neurotransmitters

    • D. 

      Troponin

  • 8. 
    Calcium comes from two sources
    • A. 

      Sarcoplasmic reticulum and golgi

    • B. 

      Extracellular space and T-tubules

    • C. 

      Extracellular space and sarcoplasmic reticulum

    • D. 

      Endoplasmic cytosol and extracellular space

  • 9. 
    __________________ is absolutely necessary for contraction.
    • A. 

      Glucose

    • B. 

      Extracellular calcium

    • C. 

      Protein kinase

    • D. 

      Troponin I

  • 10. 
    Calcium can enter the cell through _______________ or  _______________.
    • A. 

      Na/Ca ATPase; diffusion

    • B. 

      Voltage gated channels; Na/Ca ATPase

    • C. 

      Voltage-gated channels; ligand gated channels

    • D. 

      Ligand gated channels; Na/Ca ATPase

  • 11. 
    L-type Ca channels are opened when
    • A. 

      The stimulus is a neurotransmitter.

    • B. 

      The stimulus is reaches hyperpolarization

    • C. 

      The stimulus initiation the smooth muscle contraction is higher than the previous stimulus.

    • D. 

      The stimulus initiating smooth muscle contraction changes the membrane potential

  • 12. 
    If the stimulus is a neurotransmitter (NT) it will bind to a specific receptor and open the ligand gated channel either direcctly or through a series of signaling events, ie norepinephrine binding to alpha 2 adrengeric receptors.
    • A. 

      True

    • B. 

      False

  • 13. 
    Postsynaptic neurons in the Barorepector pathway from sympathetic division release the NT ________________which is ____________.
    • A. 

      Norepinephrine; inhibitory

    • B. 

      Epinephrine; inhibitory

    • C. 

      Epinephrine; excitatory

    • D. 

      Norepinephrine; excitatory

  • 14. 
    The parasynthetic neurons release in the Baroreceptor Pathway _____________, which is ________________.
    • A. 

      Norepinephrine; inhibitory

    • B. 

      Acetylcholine; excitatory

    • C. 

      Epinephrine; excitatory

    • D. 

      Acetylcholine; inhibitory

  • 15. 
    Extracellualr Ca and intracellular Ca are controlled ________of each other.
    • A. 

      Dependently

    • B. 

      Independently

    • C. 

      By hydolysis

    • D. 

      By phosphorylation

  • 16. 
    Calcium induced calcium release in smooth muscle is exactly the  same in
    • A. 

      Skeletal muscle

    • B. 

      Cardiac muscle

    • C. 

      Metabolism of chylomicrons

    • D. 

      Lipoproteins

  • 17. 
    Calcium induced calcium released means that extracellular calcium enters the cell and activated ryanodine receptors in the SR membrane opening the calcium channels.
    • A. 

      True

    • B. 

      False

  • 18. 
    Hormones binding to receptors on cell membrane causes the intracellular formation of ________________, which binds to ____________ receptors on the SR membrane causing a release calcium.
    • A. 

      Apo B100; B/E

    • B. 

      Inositol 1,4,5-triphosphate (IP3); IP3

    • C. 

      Apo E; B/E

    • D. 

      G proteins; G protein

  • 19. 
    Smooth muscle can not be made to contract in the absence of an action potential.
    • A. 

      True

    • B. 

      False

  • 20. 
    In order for a strong contaction to occur, an action potentials' ability to have increased influx of Na through voltage gated channels is essential.
    • A. 

      True

    • B. 

      False

  • 21. 
    Prolonged contractions of smooth muscles, needs extracellular calcium because SR does not have enough calcium to maintain contraction for long periods of time.
    • A. 

      True

    • B. 

      False

  • 22. 
    Ligand gated channels leads to calcium entering and depolarization of membrane causing opening of voltage gated channels calcium channels, furthing the influx of calcium lead to an action potential in smooth muscle.
    • A. 

      True

    • B. 

      False

  • 23. 
    Calcium in the cytoplasm binds to
    • A. 

      Protein kinase

    • B. 

      Calcitonin

    • C. 

      Calmodulin

    • D. 

      Myosin light chain phosphatase

  • 24. 
    Ca-calmodulin complex binds to ____________and activates the enzyme. Active _______ phosphorylates the light chain in the head region of the myosin molecule causing a conformational change that allows myosin to bind to actin.
    • A. 

      MLCP; MLCP

    • B. 

      MLCK; MLCK

    • C. 

      MLCP; MLCK

    • D. 

      Calmodulin P; troponin C

  • 25. 
    Cross bridge and power stroke in smooth muscle is the exact same as in ___________.
    • A. 

      Cardiac muscle

    • B. 

      Skeletal muscle

    • C. 

      Myosin ATPase

    • D. 

      Hemoglobin production

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