defecation is the final act of digestion, in which the organism removes solid, semisolid, or liquid waste material from the digestive tract through the anus.
Humans release feces with varying frequency from several times every day up to several times a week. A wave of muscle contraction (known as peristaltic ) in the colon wall moves dirt through the gastrointestinal tract to the rectum. Undigested food can also be disposed of in this way, in a process called egestion .
Open defecation, the practice of defecation outside without any toilet, is still widespread in some developing countries, for example in India.
Video Defecation
Description
Physiology
The ampulla rectum (anatomically also: ampulla recti ) temporarily stores sewage waste. When the garbage fills the rectum and widens the rectal wall, the receptors stretching the nervous system on the rectum wall stimulate the urge to defecate. This urge to defecate arises from the reflex contraction of the rectal muscles, internal anal sphincter relaxation, and early contraction of the external anal sphincter skeletal muscle. If the urge is not acted upon, the matter in the rectum is often returned to the colon with peristalsis, where more water is absorbed and the dirt is stored until subsequent mass peristaltic movements of the transverse and descending colon. If bowel movements are delayed for a long time, feces may harden, causing constipation. If bowel movements occur too quickly, before excess fluid is absorbed, diarrhea may occur.
When the rectum is full, an increase in intra-rectal pressure separates the walls of the anal canal, allowing the faeces to enter the ducts. The rectum is shorter because the material is forced into the anal opening and the peristaltic waves push the impurities out of the rectum. The internal and external anal sphincters along with the puborectal muscles allow the faeces to be passed by the muscles pulling the anus up into the outflow stool.
Defecation is usually helped by taking a deep breath and trying to expel this air against the closed glottis (Valsava maneuver). Contraction of the expiratory chest muscles, diaphragms, abdominal wall muscles, and the pelvic diaphragm put pressure on the gastrointestinal tract. Ventilation at this point temporarily stops when the lungs push the chest diaphragm downward to exert pressure. Chest X-ray pressure is increased and as a reflex response the amount of blood pumped by the heart decreases. Death has been known to occur in cases where defecation causes blood pressure to increase enough to cause an aneurysm to rupture or remove a blood clot (see thrombosis). Also, in releasing blood pressure maneuver Valsalva falls; This, coupled with a quick stand to leave the toilet, may result in a power outage.
During defecation, the external sphincter muscles relax. The muscles of anal sphincter and urethra are closely related. Experiments by Harrison Weed at Ohio State University Medical Center have shown that they can only be contracted together, not individually, and both show relaxation while urinating. This explains why bowel movements are often accompanied by urination.
Voluntary and accidental control
Defecation can be intentional or voluntary. Young children learn voluntary control through the toilet training process. Once trained, loss of control, called fecal incontinence, may be caused by physical injury, nerve injury, previous surgery (such as episiotomy), constipation, diarrhea, loss of storage capacity in the rectum, intense fear, inflammatory bowel disease, psychological or neurological factors, childbirth, or death.
Maps Defecation
Posture
The position and modalities of defecation depend on culture. The squat toilets are used by most of the world, including most of Africa, Asia, and the Middle East. The use of toilet sitting in the Western world is a relatively new development, beginning in the 19th century with the advent of water pipes inside the house.
Health aspects
Trying to force the expiration of the breath against the closed air passages (valsava maneuvers) is sometimes done to induce bowel movements while in the toilet. Cardiac arrest and other cardiovascular complications can occur in rare cases as it tries to defecate using valsalva maneuvers. Retalopathy Valsalva is another pathological syndrome associated with Valsalva maneuver.
Society and culture
Rectal cleansing after bowel movements
The anus and buttocks can be cleaned after defecation with toilet paper, similar paper products, or other absorbent materials. In many cultures, such as Hinduism and Muslims, water is used for cleaning the rectum after a bowel movement, either in addition to using toilet paper or exclusively. When water is used for anal cleaning after defecation, toilet paper can be used to dry the area afterwards.
Mythology and traditions
Some people have significant cultural stories where defecation plays a role. As an example:
- In the legend of Alune and Wemale from Seram Island, Maluku Province, Indonesia, Hainuwele mythical girl throws a lot of valuables.
- One of the traditions of Catalonia (Spain) relates to caganer , a statue depicting the defecation that appears in Jesus' birth scene in Catalonia and the surrounding area with Catalan culture. The exact origins of caganer are missing, but tradition has existed since at least the 18th century.
See also
References
Further reading
- Deeb, Benjamin (2004). Healthy for Core: How to Measure the Effective Stool. Greenwood Press.
- Widmaier, Raff & amp; Strang (2006). Human Physiology Vanders, the mechanism of body function. Chapter 15. McGraw Hill.
Source of the article : Wikipedia
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