What are the muscles that found at openings of body collectively called?

The sphincter muscles are the muscles that found at openings of the body collectively. They are responsible for controlling the flow of substances in and out of the body. The most common type of sphincter muscle is the circular muscle, which surrounds an opening and can contract to close it off. Other types of sphincter muscles include the longitudinal muscle, which runs along the length of an opening, and the oblique muscle, which runs diagonally across an opening.

Some of the most important sphincter muscles in the body include:

* The anal sphincter muscles, which control the flow of stool out of the rectum.

* The bladder sphincter muscles, which control the flow of urine out of the bladder.

* The esophageal sphincter muscles, which control the flow of food and drink into the stomach.

* The laryngeal sphincter muscles, which control the flow of air into and out of the lungs.

Sphincter muscles are essential for maintaining homeostasis in the body. They help to regulate the flow of fluids, gases, and solids in and out of the body, and they also help to protect the body from infection.