Physiology Quiz -
Smooth Muscle - Part 1

Smooth muscle is critically important to the function of the digestive system, reproductive system, respiratory system, vascular system (but not capillaries because their walls are composed of only a single layer of endothelial cells), urinary bladder, as well as many other organs. Test your basic knowledge of smooth muscle physiology by taking this simple quiz.

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(1) In smooth muscle contraction, the majority of calcium (Ca²⁺) needed for contraction enters the cell from the extracellular fluid.

	True
	False

(2) In smooth muscle, when the cytoplasmic calcium (Ca²⁺) concentration is elevated, Ca²⁺ binds to this regulatory protein in order to initiate muscle contraction.

(3) Transverse (t) tubules are present in smooth muscle.

	True
	False

(4) Which one of the following is NOT true about smooth muscle?

	(A) Both actin and myosin are found in the smooth muscle cell cytoplasm, but these are not arranged in sarcomere units.
	(B) The needed calcium (Ca²⁺) for contraction comes primarily from the extracellular fluid.
	(C) Similar to skeletal muscle cells, smooth muscle cells are capable of only all-or-nothing twitches.
	(D) Smooth muscle cell contractions are weak but sustained.
	(E) Unlike the myosin molecules of skeletal muscle cells, the myosin found in smooth muscle cells is quite long, with its entire length covered with myosin head groups.

(5) A single twitch of a smooth muscle cell can last:

	(A) 1 - 2 ms
	(B) 10 - 100 ms
	(C) 200 - 300 ms
	(D) 0.5 - 5 s
	(E) All of the above are possible

Checking your answers...

Posted: Monday, February 2, 2015
Last updated: Tuesday, March 11, 2025

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Physiology Quiz -Smooth Muscle - Part 1

Physiology Quiz -
Smooth Muscle - Part 1