A sphincter is a ____.
A)ring of smooth muscle in a tubular organ or body opening
B)strap of connective tissue that connects bone to bone
C)strap of connective tissue that connects muscle to bone
D)ring of muscle at a body opening
E)longitudinal muscle at a body opening

Question

Quizplus · Accepted Answer

A sphincter is a ring of muscle that serves as a valve to control the opening and closing of a body opening, such as the anal sphincter or the lower esophageal sphincter.

A Sphincter Is a ____