Which of the following is involved in the process of muscle relaxation
a. acetylcholinesterase destroys acetylcholine to allow the muscle membrane to return to resting potential.
b. Ca2+ is released by the sarcoplasmic reticulum
c. cross bridge formation increases
d. both (a) and (b) above.
e. all of these answers.
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Question 2) The intrinsic nerve plexuses
a. produce spontaneous depolarization of the smooth muscle cells in the wall of the digestive tract.
b. are located in the mucosa.
c. coordinate local activity in the digestive tract.
d. both (a) and (c) above.
e. all of these answers.
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Question 3) Which of the following is involved in the process of muscle relaxation
a. acetylcholinesterase destroys acetylcholine to allow the muscle membrane to return to resting potential.
b. Ca2+ is actively taken up by the lateral sacs of the sarcoplasmic reticulum when there is no longer a local action potential.
c. the cross bridges from the thick filaments bind to the thin filaments and bend in such a way as to return the filaments to their original resting position.
d. both (a) and (b) above.
e. all of these answers.
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Question 4) The serosa is the
a. abdominal cavity containing the stomach.
b. blood supply to the stomach.
c. inner lining of the digestive tract.
d. layer of smooth muscle of the digestive tract.
e. outer connective tissue covering of the digestive tract.
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Question 5) Why are you able to repeatedly contract and relax your muscles of respiration, allowing you to breathe in and breathe out?
a. As soon as all of the Ca2+ stored in the lateral sacs of the sarcoplasmic reticulum is used up, muscle relaxation occurs.
b. After the muscle cell becomes excited, acetylcholinesterase rapidly destroys acetylcholine.
c. When there is no longer a local action potential in the muscle cell, Ca2+ is actively transported back into the lateral sacs of the sarcoplasmic reticulum, and muscle relaxation occurs.
d. Both (b) and (c) above.
e. All of these answers.
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Question 6) Which tissue layer provide for primary digestive motility?
a. mucosa.
b. submucosa.
c. muscularis mucosa.
d. muscularis externa.
e. mesentery.
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Question 7) What would happen if ATP supplies became very low in a muscle cell?
a. tension development would decrease.
b. cross bridges would not detach from actin.
c. possibly contractures.
d. in death, rigor mortis.
e. all these answers.
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Question 8) Which of the following organs does not produce secretions that are directly involved in chemical digestion?
a. esophagus.
b. stomach.
c. pancreas.
d. small intestine.
e. liver
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Question 9) Which of the following is not involved in the relaxation of muscle?
a. when acetylcholine is destroyed by acetylcholinesterase.
b. when there is no longer a local action potential.
c. when the T tubules actively take up the Ca2+ that had been released.
d. when the actin and myosin molecules are no longer bound together.
e. when the troponin-tropomyosin complex slips back into its blocking position.
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Question 10) Digestion of polysaccharides
a. is accomplished using enzymes.
b. begins in the mouth
c. is finished in the stomach
d. both (a) and (b) above.
e. both (a) and (c) above.
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