Musculus Sphincter Ani Internus (Noun)
Meaning
An internal ring of smooth muscle formed by circular fibers of the rectum.
Classification
Nouns denoting body parts.
Examples
- The musculus sphincter ani internus is a component of the anal sphincter, providing involuntary control over the opening and closing of the anus.
- In humans, the musculus sphincter ani internus is composed of smooth muscle fibers arranged in a circular fashion around the anal canal.
- The musculus sphincter ani internus is an involuntary muscle, meaning its contractions are not under conscious control.
- During continence, the musculus sphincter ani internus maintains a resting tone that helps to prevent involuntary defecation.
- The musculus sphincter ani internus relaxes during defecation to allow for the passage of stool from the rectum.