The ________ is composed of smooth muscle fibers and is not under voluntary control.

Question

Quizplus · Accepted Answer

The internal anal sphincter is composed of smooth muscle fibers and is not under voluntary control, unlike the external anal sphincter which is composed of skeletal muscle fibers and can be voluntarily contracted or relaxed. The rectum, sigmoid flexure, and anal canal are parts of the large intestine and do not directly relate to the internal anal sphincter.

The ________ Is Composed of Smooth Muscle Fibers and Is