Select the description below that illustrates a difference between a sphincter and circular muscle.
A) A sphincter is a thickening of circular muscle that can prevent the movement of digesting materials while circular muscle is involved in propulsion digesting material.
B) Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract.
C) A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue.
D) Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions.

Question

Quizplus · Accepted Answer

A sphincter is a specialized thickening of the circular muscle layer that can prevent the movement of digesting materials, while circular muscle is involved in the propulsion of digesting material. The other choices are either incorrect or incomplete in their descriptions.

Select the Description Below That Illustrates a Difference Between a Sphincter