In anatomy, the anus (from Latin ānus "ring (circle)^[1][2], anus") is the external opening of the rectum. Anatomy (from the Greek anatomia, from ana separate apart from and temnein, to cut up cut open is a branch of Biology that is the consideration Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the Large intestine in some Mammals Closure is controlled by sphincter muscles. A sphincter is a structure usually a circular Muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological Muscle (from Latin musculus, diminutive of mus "mouse" is contractile tissue of the body and is derived from the Feces are expelled from the body through the anus during the act of defecation, which is the primary function of the anus. Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract Most animals—from simple worms to elephants and humans—have a tubular gut, with a mouth at one end and an anus at the other. The mouth, buccal cavity, or oral cavity is the first portion of the Alimentary canal that receives food and begins digestion by mechanically breaking up

The anus plays a role in sexuality, though attitudes towards anal sex vary and it is even illegal in some countries. Anal sex most often refers to the sex act involving insertion of the Penis into the Rectum. The anus is also the site of potential infections and other conditions including cancer. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled The subject is often considered a taboo part of the body, and it is known by a large number of usually vulgar slang terms. A taboo is a strong Social prohibition (or ban) against words objects actions or discussions that are considered undesirable or offensive by a group culture " Vulgarism " (also called scurrility) derives from Latin vulgun, the "mean folk" and has carried into English its original Slang is the use of highly informal Words and expressions that are not considered standard in the speaker's Dialect or Language. The traditional polite synonym for anus was fundament, though this euphemism is rarely heard now that medical terms are widely acceptable. A euphemism is a substitution of an agreeable or less offensive expression in place of one that may offend or suggest something unpleasant to the listener or in the case of doublespeak

Contents 1 Role in defecation 2 Role in sexuality 3 Puberty 4 Health 5 Cosmetics 6 Pathology 7 Additional images 8 See also 9 References

Role in defecation

Main article: Defecation

Intra-rectal pressure builds as the rectum fills with feces, pushing the feces against the walls of the anal canal. Defecation is the final act of Digestion by which organisms eliminate solid semisolid or liquid Waste material ( Faeces) from the Digestive tract The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the Large intestine in some Mammals The anal canal is the terminal part of the Large intestine. It is situated between the Rectum and Anus, below the level of the Pelvic diaphragm Contractions of abdominal and pelvic floor muscles can create intra-abdominal pressure which further increases intra-rectal pressure. The internal anal sphincter (an involuntary muscle) responds to the pressure by relaxing, thus allowing the feces to enter the canal. The Sphincter ani internus (or internal anal sphincter) is a muscular ring which surrounds about 2 The rectum shortens as feces are pushed into the anal canal and peristaltic waves push the feces out of the rectum. In the Esophagus After food is chewed into a bolus it is swallowed to move it into the esophagus Relaxation of the internal and external anal sphincters allows the feces to exit from the anus, finally, as the levator ani muscles pull the anus up over the exiting feces. The Levator ani is a broad thin Muscle, situated on the side of the Pelvis.

To prevent diseases of the anus and to promote general hygiene, humans often clean the exterior of the anus after emptying the bowels. A rinse with water from a bidet or a wipe with toilet paper are often used for this purpose. A bidet is a low-mounted Plumbing fixture or type of Sink intended for Washing the Genitalia, inner Buttocks, and Anus. Toilet paper is a soft paper product used to maintain Personal hygiene after human Defecation or Urination.

Role in sexuality

Main article: Anal sex

The anus has a relatively high concentration of nerve endings and is an erogenous zone. Anal sex most often refers to the sex act involving insertion of the Penis into the Rectum. A nerve is an enclosed cable-like bundle of peripheral Axons (the long slender projections of Neurons. An erogenous zone is an area of the Human body that has heightened Sensitivity and stimulation of which normally results in sexual response. Sigmund Freud's theory of psychosexual development, for example, described an anal stage, hypothesizing that toddlers derive pleasure from retaining and expelling feces. Sigmund Freud (ˈziːkmʊnt ˈfʁɔʏt born Sigismund Shlomo Freud (May 6 1856 &ndash September 23 1939 was an Austrian Psychiatrist who founded The concept of psychosexual development, as envisioned by Sigmund Freud at the end of the nineteenth and the beginning of the twentieth century is a central element in his sexual The anal stage in Psychology is the term used by Sigmund Freud to describe the development during the second year of life in which a child's pleasure and This is the source of the term "anal" and the derived, derogatory vulgarism "anal-retentive". Words and phrases are pejorative if they imply disapproval or contempt The term anal-retentive (or anally retentive, anal retentive) commonly abbreviated to "anal" is used Conversationally

Anal intercourse can be pleasurable for both the insertive partner and the receptive partner. Anal sex most often refers to the sex act involving insertion of the Penis into the Rectum. For the receptive partner, pleasure from anal intercourse is also thought to be related to the shared wall between the rectum and the vagina (for females) as well as the G-spot or prostate (for males). The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus The Gräfenberg spot, or G-spot, is a female Erogenous zone which when stimulated leads to high levels of sexual arousal and powerful Orgasms The prostate (from Greek προστάτης - prostates, literally "one who stands before" "protector" "guardian" is a For the insertive partner, the tightness of the anus is often said to be a source of pleasure in penetrative anal sex. Anal intercourse, sometimes referred to as sodomy or buggery, is a human sexual activity, but is considered taboo in a number of moral systems, and it has been, and in some jurisdictions continues to be, a crime carrying severe punishment. Sodomy (ˈsɒdəmi is a term used today predominantly in Law (derived from traditional Christian usage to describe the act of Anal intercourse, Oral intercourse The English term Buggery is very close in meaning to the term Sodomy, and is often used interchangeably in law and popular speech A taboo is a strong Social prohibition (or ban) against words objects actions or discussions that are considered undesirable or offensive by a group culture In Law, jurisdiction (from the Latin ius iuris meaning "law" and dicere meaning "to speak" is the practical Authority

Anal sexual activity need not include penetration. The anus also plays an important role in facesitting, coprophilia and anilingus. Facesitting, also known as queening, is a Sexual practice in which one partner sits on or over the other's face typically to allow or force oral-genital Coprophilia (from Greek κόπρος kópros - excrement and φιλία filía - liking fondness) also called scat, is the Paraphilia Anal–oral sex, also referred to or described as anal–oral contact or anilingus (from anus + lingus (Latin Lingere:to lick also

Anal stretching can stimulate the nerves around the anus and can be considered pleasurable. Care must be taken to maintain elasticity.

Lubricant is widely regarded as a necessity while performing anal sex.

Puberty

During puberty, as testosterone triggers androgenic hair growth on the body, pubic hair begins to appear around the anus. Androgenic hair, colloquially Body hair, is the Terminal hair on the Human body developed during and after Puberty. Although initially sparse, it fills out by the end of puberty, if not earlier.

Health

Hygiene is important for good anal health and anal sex. Washing with a mild soap and water will keep the anus clean. Harsh soaps or wiping vigorously with toilet paper can irritate the skin around the anus, making it itchy or sore. Pinworms are sometimes the source of anal itching. The pinworm (Genus Enterobius) also known as threadworm is a Parasitic Roundworm of the phylum Nematoda. Pruritus ani is the irritation of the skin at the exit of the Rectum, known as the Anus, causing the desire to scratch

Care should be taken not to strip the anus of natural oils that keep the skin around the opening supple and elastic.

Penetration with a penis or sex toy can irritate or tear the inside of the anus. A sex toy is an object or device that is primarily used in facilitating human sexual pleasure. Lubrication is often recommended to ease penetration. The risk of injury to the anal sphincter should be a concern. Similarly if the anus is torn, this can occasionally cause a fistula formation which can not only cause fecal leaking, but also can be very difficult to treat. An Anal Fistula is an abnormal connection between the Epithelialised surface of the Anal canal and (usually the Perianal skin

Kegel exercises can improve the tone of the outer sphincter muscle^[3]. A Kegel exercise, named after Dr Arnold Kegel, consists of contracting and relaxing the muscles which form part of the Pelvic floor (sometimes called the "Kegel

Cosmetics

Shaving, trimming, depilatory (hair removal), or Brazilian waxing can clear the perineum of hair. Hair removal describes any method of removing Hair, especially from the human body Bikini Waxing refers to the removal of Hair at the top of the Leg, below the Navel, and in the bikini area, otherwise known as the

Anal bleaching is a process in which the anus and perineum, which may darken with puberty depending on individual genetics, is lightened for a more youthful appearance. Anal bleaching is the practice of bleaching the Pigmentation of the skin of light-skinned people around the Anus. In Human anatomy, the perineum is generally defined as the surface region in both males and females between the Pubic symphysis and the Coccyx. This practice has been linked to skin cancer, and other health problems.

True Anal piercing is rare because it may interfere with the function of the anus, however surface piercings of the perineum are easier to care for and much more common. An anal piercing is a Body piercing in the Anus or the surrounding area

Pathology

Diseases of the anus include anal cancer, abscess, warts, fistula, anal fissure, itching and hemorrhoid. Anal cancer is a type of Cancer which arises from the Anus, the distal orifice of the Gastrointestinal tract. An abscess (abscessus is a collection of Pus (dead Neutrophils) that has accumulated in a cavity formed by the tissue on the basis of an infectious process A wart (also known as verruca) is generally a small rough Tumor, typically on hands and feet but often other locations that can resemble a Cauliflower An Anal Fistula is an abnormal connection between the Epithelialised surface of the Anal canal and (usually the Perianal skin An anal fissure is an unnatural crack or tear in the Anus skin Itch ( Latin: pruritus) is an unpleasant Sensation that evokes the desire or Reflex to scratch Hemorrhoids ( AmE) haemorrhoids ( BrE) emerods, or piles are varicosities or swelling and Inflammation The anus is also a frequent site of sexually transmitted infections. A sexually transmitted disease ( STD) or venereal disease ( VD) is an illness that has a significant probability of transmission between Humans These benefit from medical intervention.

Birth defects of the anus include stenosis and imperforation. A congenital disorder is a disease or disorder that is present at birth A stenosis ( Plural: stenoses; from Ancient Greek στένωσις "narrowing" is an abnormal narrowing in a Blood vessel An imperforate anus or anal atresia is a Birth defect in which the Rectum is malformed These benefit from surgical intervention.

Damaged anal sphincter (patulous anus in more severe cases) — caused by careless or sometimes necessarily sacrificial surgery in the perineal region or by rough/abrupt penetration in anal sex — can lead to flatus and/or fecal incontinence, chronic constipation and, ultimately, megacolon. The anus is an opening at the opposite end of an Animal 's Digestive tract from the Mouth. In Human anatomy, the perineum is generally defined as the surface region in both males and females between the Pubic symphysis and the Coccyx. Anal sex most often refers to the sex act involving insertion of the Penis into the Rectum. Flatulence is the production of a mixture of gases in the digestive tract of Mammals that are byproducts of the digestion process Fecal incontinence is the loss of regular control of the Bowels. Constipation, costiveness, or irregularity, is a condition of the Digestive system in which a person (or animal experiences hard Feces that Megacolon is an abnormal dilatation of the colon (a part of the large Intestines that is not caused by mechanical obstruction

In psychology the Freudian term anal fixation is used. Psychology (from Greek grc ψῡχή psȳkhē, "breath life soul" and grc -λογία -logia) is an Academic and Sigmund Freud (ˈziːkmʊnt ˈfʁɔʏt born Sigismund Shlomo Freud (May 6 1856 &ndash September 23 1939 was an Austrian Psychiatrist who founded The term anal-retentive (or anally retentive, anal retentive) commonly abbreviated to "anal" is used Conversationally

Additional images

Muscles of the male perineum

Muscles of the female perineum

The posterior aspect of the rectum and anus exposed by removing the lower part of the sacrum and the coccyx

See also

• Anal stage (Freudian psychosexual stage)
• Arse
• Cloaca
• Digestive system
• Flatulence
• Hemorrhoid
• Anococcygeal nerve
• Coccyx
• Coccydynia (coccyx pain, tailbone pain)

References

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