August 13, 2022

Anus (Latin anus) - in anatomy, the end opening of the gastrointestinal tract. The anus is closed by a chain of strong, circular muscles that make up the anal sphincter (a distinction is made between the internal anal sphincter and the external anal sphincter). The primary function of the anus is to empty the gastrointestinal tract of faeces in the process of defecation. In humans, the male anus is more hairy and more colored. In some animals - amphibians, reptiles and birds, as well as fish and monotails - instead of the anus there is a cloaca, into which the digestive, excretory and sexual systems pass. Birds mate most often by touching each other with cesspools.

Diseases of the anus

The mucosa that lines the intestines in the anus passes into the skin; here it is particularly vascularized and prone to the formation of hemorrhoids. Perianal abscesses may also form, sometimes complicated by perianal fistulas that are difficult to heal. The mucosa may rupture when the anal opening is overstretched. The area of ​​the anus can also be the site of chafing or chafing, e.g. in the case of fungal infections. Anal pruritus (Latin pruritus ani) of unknown cause may occur; sometimes the itching is caused by pinworms. Occasionally, there is an atrophy of the anus (see anal and rectal malformations), requiring surgery in the first days of a newborn's life. Scar stenosis may occur after improperly performed operations. Faecal incontinence may occur as a result of sphincter damage or for neurological reasons (e.g. traumatic spinal cord injury).

In other mammals

See also

rectum anal phase latrine intestinal gas coccyx anal sex