👉 The anal sphincter is a ring-like muscle structure located at the bottom of the rectum, controlling the opening and closing of the anus. It consists of two parts: the internal sphincter, which is involuntary and composed of smooth muscle, and the external sphincter, which is voluntary and made up of skeletal muscle. The internal sphincter maintains constant, low pressure to keep stool contained, while the external sphincter can be consciously relaxed or contracted to manage bowel movements. Together, these muscles ensure that the anal canal remains sealed when needed and allows controlled opening for defecation.
