AskDefine | Define bile

Dictionary Definition

bile n : a digestive juice secreted by the liver and stored in the gallbladder; aids in the digestion of fats [syn: gall]

User Contributed Dictionary

English

Pronunciation

Etymology

Mid 16th century, via from bilis.

Noun

  1. A bitter brownish-yellow or greenish-yellow secretion produced by the liver, stored in the gall bladder, and discharged into the duodenum where it aids the process of digestion.
  2. bitterness of temper; ill humour; irascibility.
  3. Two of the four humours, black bile or yellow bile, in ancient and medieval physiology.

Synonyms

Translations

Italian

Noun

  1. In the context of "physiology|lang=it": bile

Scottish Gaelic

Noun

bile , gen bile, p bilean
  1. A lip of the mouth.
    Thàinig faite-gàire bheag gu a bhilean. — A small smile came to her lips.

Turkish

Conjunction

bile

Extensive Definition

Bile or gall is a bitter, yellow or green alkaline fluid secreted by hepatocytes from the liver of most vertebrates. In many species, bile is stored in the gallbladder between meals and upon eating is discharged into the duodenum where the bile aids the process of digestion of lipids.

General infomation (summary)

Bile has various components, some of which is produced by hepatocytes (liver cells). Its constituents include:
  • Water
  • Cholesterol
  • Bile pigments
  • Bile salts
The bile salts sodium glycocholate and sodium taurocholate are produced by the liver from cholesterol. They are secreted in bile by hepatocytes along the bile canaliculi, which then join the bile duct, and goes into the gall bladder. Ordinarily the concentration of bile salts in bile is 0.8%, however the gall bladder removes water from the bile, concentrating it between meals. It concentrates it up to 5 times (increasing concentration to 4%), before contracting the walls and releasing it into the duodenum once chyme has entered the small intestine.

Components- in more detail

The components of bile:

Production

Bile is produced by hepatocytes in the liver, draining through the many bile ducts that penetrate the liver. During this process, the epithelial cells add a watery solution that is rich in bicarbonates that dilutes and increases alkalinity of the solution. Bile then flows into the common hepatic duct, which joins with the cystic duct from the gallbladder to form the common bile duct. The common bile duct in turn joins with the pancreatic duct to empty into the duodenum. If the sphincter of Oddi is closed, bile is prevented from draining into the intestine and instead flows into the gallbladder, where it is stored and concentrated to up to five times its original potency between meals. This concentration occurs through the absorption of water and small electrolytes, while retaining all the original organic molecules. Cholesterol is also released with the bile, dissolved in the acids and fats found in the concentrated solution. When food is released by the stomach into the duodenum in the form of chyme, the gallbladder releases the concentrated bile to complete digestion.
The human liver can produce close to one litre of bile per day (depending on body size). 95% of the salts secreted in bile are reabsorbed in the terminal ileum and re-used. Blood from the ileum flows directly to the hepatic portal vein and returns to the liver where the hepatocytes resorb the salts and return them to the bile ducts to be re-used, sometimes two to three times with each meal.

Physiological functions

Bile salts are composed of a hydrophilic side, and a hydrophobic side. This means that they are more likely to aggregate to form micelles, with the hydrophobic sides towards the centre and hydrophilic towards the outside. In the centre of these micelles are triglycerides, which are separated from a larger globule of lipid, as shown in the diagram.
Pancreatic lipase is able to get to the molecules of triglyceride through gaps between the bile salts, providing a largely increased surface area for digestion. Ordinarily, the micelles in the duodenum have a diameter of around 14-33μm. However, it is possible for these to be much smaller, as small as 160nm when using artificial means.
Should bile not be present in the duodenum, not all of the lipid is able to be digested during digestion, and a lot of it is passed out in feces. As a result the time taken for the lipid to be broken down would be greatly increased if there was no bile present in the duodenum. This is how the body is able to efficiently digest and absorb lipids for metabolism.
Bile acts to some extent as a detergent, helping to emulsify fats (increasing surface area to help enzyme action), and thus aids in their absorption in the small intestine. The most important compounds are the salts of taurocholic acid and deoxycholic acid. Bile salts combine with phospholipids to break down fat globules in the process of emulsification by associating its hydrophobic side with lipids and the hydrophilic side with water. Emulsified droplets then are organized into many micelles which increases absorption. Since bile increases the absorption of fats, it is an important part of the absorption of the fat-soluble vitamins D, E, K and A. Besides its digestive function, bile serves as the route of excretion for the hemoglobin breakdown product (bilirubin) created by breakdown of erythrocytes, which are conjugated by glucuronidation in the liver ; it also neutralises any excess stomach acid before it enters the ileum, the final section of the small intestine. Bile salts are also bacteriocidal to the invading microbes that enter with food.

Bile soaps

Bile from slaughtered animals can be mixed with soap. This mixture, called bile soap, can be applied to textiles a few hours before washing and is a traditional and rather effective method for removing various kinds of tough stains.

Abnormal conditions associated with bile

  • The cholesterol contained in bile will occasionally accrete into lumps in the gall bladder, forming gallstones.
  • On an empty stomach, for example, after repeated vomiting caused by excessive consumption of alcohol, a person's vomit may be green or dark yellow, and very bitter. The bitter and greenish component is bile.  (The color of bile is often likened to “fresh-cut grass,” but in a vomit it may be mixed with other components in the stomach to look greenish yellow or dark yellow.)
  • In the absence of bile, fats become indigestible and are instead excreted in feces, a condition called steatorrhea. Feces lack their characteristic brown colour and instead are white or grey, and greasy. Steatorrhea can lead to deficiencies in essential fatty acids and fat-soluble vitamins. In addition, past the small intestine (which is normally responsible for absorbing fat from food) the gastrointestinal tract and gut flora are not adapted to processing fats, leading to problems in the distal parts of the intestine.

Four humors

Yellow bile (sometimes called ichor) and black bile were two of the four vital fluids or humors of ancient and medieval Greco-Roman alternative medicine (the other two were phlegm and blood). The Latin names for the terms gave rise to the words "choler" (bile) and "melancholia" (black bile). Excessive bile was supposed to produce an aggressive temperament, known as "choleric". This is the origin of the word "bilious." Depressive and other mental illnesses (melancholia) were ascribed to a bodily surplus of black bile. This is the origin of the word "melancholy."

Footnotes

References

bile in Arabic: صفراء
bile in Bosnian: Žuč
bile in Catalan: Bilis
bile in Czech: Žluč
bile in Danish: Galde
bile in German: Galle
bile in Spanish: Bilis
bile in Esperanto: Galo
bile in French: Bile
bile in Ido: Bilo
bile in Indonesian: Empedu
bile in Icelandic: Gall
bile in Italian: Bile
bile in Pampanga: Bile
bile in Latin: Bilis
bile in Lithuanian: Tulžis
bile in Hungarian: Epe
bile in Dutch: Gal (stof)
bile in Japanese: 胆汁
bile in Norwegian: Galle
bile in Norwegian Nynorsk: Galle
bile in Polish: Żółć
bile in Portuguese: Bile
bile in Russian: Жёлчь человека
bile in Simple English: Bile
bile in Slovak: Žlč
bile in Slovenian: Žolč
bile in Serbian: Жуч
bile in Finnish: Sappi
bile in Swedish: Galla
bile in Telugu: పైత్యరసం
bile in Thai: น้ำดี
bile in Vietnamese: Mật
bile in Turkish: Safra
bile in Ukrainian: Жовч
bile in Chinese: 胆汁

Synonyms, Antonyms and Related Words

absorption, acerbity, acid, acidity, acidulousness, acrimony, anger, animosity, asperity, assimilation, autacoid, bad humor, bad temper, biliousness, bitter resentment, bitterness, bitterness of spirit, causticity, chalone, choler, corrosiveness, digestion, digestive secretion, digestive system, discontent, endocrine, gall, gastric juice, gastrointestinal tract, gnashing of teeth, hard feelings, heartburning, hormone, ill humor, ill nature, ill temper, ingestion, intestinal juice, liver, mucus, pancreas, pancreatic digestion, pancreatic juice, predigestion, prostatic fluid, rancor, rankling, rheum, saliva, salivary digestion, salivary glands, salivary secretion, secondary digestion, semen, slow burn, soreness, sourness, sperm, spleen, tears, thyroxin, virulence
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