Anus

What is the anus and what is its structure?

The anus is the final part of the digestive system, located at the bottom of the rectum, through which feces is passed. It is surrounded by a muscular ring called the sphincter, which relaxes during defecation, allowing feces to exit. The inner walls of the anus are covered with squamous cells known as squamous cells; where most cases of anal canal cancer occur. The area where the anus transitions into the skin is called the anal border and is often the site of the initial manifestations of cancer.

Anatomical structure and function of the anus

Epithelial covering and protective function

The inner lining of the anus consists of epithelial cells, which fulfil important protective functions, as they prevent mechanical damage and irritation of tissues that occur in contact with faeces and excretions. In addition, the epithelium helps to maintain the balance of microflora and prevents the development of inflammation and pathogenic microorganisms.

Muscular structures and control of defecation

The anus is surrounded by two major sphincters that provide control over bowel emptying.

• The internal sphincter consists of smooth muscle and works on a reflexive level. It holds the contents of the rectum until the body is ready to defecate.

• The external sphincter is a transverse striated muscle controlled by the mind. It allows the defecation process to be controlled and postponed when necessary, providing an additional level of regulation.

Hemorrhoidal veins and blood circulation

Blood vessels in the anal region, including hemorrhoidal veins, provide blood supply to the tissues and keep them normal. However, impaired blood flow, inflammation or dilation of these veins can lead to hemorrhoids accompanied by pain, itching and bleeding.

Functions and features of the anal area

The anal region is highly sensitive due to the large number of nerve endings. These receptors play an important role in recognizing the state of the intestinal contents - liquid, gaseous or solid - and control the emptying process. The sensitivity also has a protective function, warning of possible damage or irritation.

In addition, the anus is an important part of the body's immune defense, as this area is home to cells that fight inflammation and infection. It is also home to beneficial microorganisms that maintain the balance of microflora and inhibit the growth of pathogenic bacteria, thus preventing the development of various diseases.

Around the anal area is located fatty tissue, which performs a shock-absorbing function; it protects the soft tissues from mechanical damage and provides additional support. Fatty tissue also contributes to the stability of the surrounding organs, preventing their displacement.

With age, the muscles and tissues of the anal region can lose tone, which can lead to defecation control problems such as fecal incontinence or rectal prolapse.

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Common Diseases of the Anal Area

1. Hemorrhoids - varicose veins in the anus area accompanied by pain, itching and bleeding.
2. Anal fissures - small lesions of the anus mucosa, causing discomfort and painful sensations during defecation.
3. Fecal incontinence - sphincter dysfunction resulting in loss of control over bowel emptying.

Functions and physiologic importance of the anus

The anus performs essential functions in the body, being responsible for the excretion of processed food residues and controlling the defecation process. Its work helps to maintain the normal activity of the digestive system and participates in the coordination of physiological processes, ensuring the overall health and stability of the body. In this sense, the sphincters of the anus play a key role in retaining fecal matter until the body is ready to excrete it. 

Due to the large number of nerve endings, the anus is highly sensitive, which allows it to accurately recognize the state of the intestinal contents, distinguishing between liquid, gas or solid masses. This sensitivity helps to regulate the emptying process, ensuring that it is carried out correctly and on time; while in addition, the muscles of the anus perform functions not only to retain feces, but also to control the release of gases. The external sphincter provides reliable control of these processes, preventing their involuntary release and maintaining the physiological stability of the body.

Anatomical and Physiological Features of the Anus

Sensitivity and Nerve Endings : The anal area is saturated with nerve receptors that respond to stimulation, creating pleasurable sensations when approached correctly. Due to its high sensitivity, the anus becomes part of sexual practices and preferences for some people.

Sphincter muscles: The sphincters of the anus play an important role in controlling contractions and relaxations; the internal sphincter functions automatically, while the external sphincter is subject to conscious control. Since these muscles can contract involuntarily, relaxation is a key component for comfort during anal stimulation.

Varieties of Anal Stimulation

Anal sex

Represents the penetration of the penis into the anus. This form of intimacy can be pleasurable, but for its safety it is important to use lubricants and condoms to avoid injury and infection.

Anal caresses

This involves stimulating the anus area with the lips or tongue. This type of stimulation is often used as an element of foreplay, increasing arousal and creating a closer bond between partners.

Toys for anal stimulation

There are special accessories such as anal plugs, balls and vibrators designed to safely explore this area. When choosing such toys, it is important to give preference to models with an extended base, which prevents accidental penetration deep into the rectum and minimizes the risk of injury.

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How can I keep my anus healthy?

The health of the anal area is an essential part of your overall health. For starters, to keep it in good condition, proper hygiene is essential; so after emptying the bowels, it is best to use soft toilet paper or wash your face with warm water, avoiding harsh soaps or scented products that can irritate or dry out the skin.

Nutrition

A balanced diet plays an important role in anal health; so consuming fibre-rich foods such as fruits, vegetables and whole grains will help prevent constipation. It is equally important to drink enough water to keep your bowels functioning properly. If you notice discomfort in the anal area after consuming spicy foods or alcohol, consider cutting down on their consumption.

Active lifestyle

Regular physical activity improves blood circulation in the pelvic area, which reduces the risk of developing haemorrhoids. Those with sedentary jobs should take short breaks to stand up and stretch - this will help prevent blood pooling in the lower body.

Healthy bowel habits

Avoid straining while emptying your bowels, as this can cause anal trauma. Consult your doctor about using mild laxatives if necessary. Establishing a regular bowel routine can minimise the risk of fissures and other complications.