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91-438: In the human liver , bile is composed of 97–98% water , 0.7% bile salts , 0.2% bilirubin , 0.51% fats ( cholesterol , fatty acids , and lecithin ), and 200 meq/L inorganic salts. The two main pigments of bile are bilirubin , which is orange-yellow, and its oxidised form biliverdin , which is green. When mixed, they are responsible for the brown color of feces . About 400 to 800 milliliters (14 to 27 U.S. fluid ounces) of bile

182-426: A benign tumour the most common type of liver tumour, thought to be congenital. A genetic disorder causing multiple cysts to form in the liver tissue, usually in later life, and usually asymptomatic, is polycystic liver disease . Diseases that interfere with liver function will lead to derangement of these processes. However, the liver has a great capacity to regenerate and has a large reserve capacity. In most cases,

273-414: A condition called steatorrhea . Feces lack their characteristic brown color and instead are white or gray, 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

364-436: A condition when bile ducts which deliver bile from the gallbladder or liver to the duodenum become obstructed. The blockage of bile might cause a buildup of bilirubin in the bloodstream which can result in jaundice . There are several potential causes for biliary obstruction including gallstones, cancer, trauma, choledochal cysts , or other benign causes of bile duct narrowing. The most common cause of bile duct obstruction

455-410: A dual blood supply from the hepatic portal vein and hepatic arteries. The hepatic portal vein delivers around 75% of the liver's blood supply and carries venous blood drained from the spleen, gastrointestinal tract, and its associated organs. The hepatic arteries supply arterial blood to the liver, accounting for the remaining quarter of its blood flow. Oxygen is provided from both sources; about half of

546-568: A few hours before washing as a traditional and effective method for removing various kinds of tough stains. Pinapaitan is a dish in Philippine cuisine that uses bile as flavoring. Other areas where bile is commonly used as a cooking ingredient include Laos and northern parts of Thailand . During the Boshin War , Satsuma soldiers of the early Imperial Japanese Army reportedly ate human livers boiled in bile. The practice of eating

637-408: A key role in this phenomenon. At birth, the liver comprises roughly 4% of body weight and weighs on average about 120 g (4 oz). Over the course of further development, it will increase to 1.4–1.6 kg (3.1–3.5 lb) but will only take up 2.5–3.5% of body weight. Hepatosomatic index (HSI) is the ratio of liver weight to body weight. In the growing fetus, a major source of blood to

728-528: A layer of unclotted erythrocytes ("blood"), a layer of white blood cells ("phlegm") and a layer of clear yellow serum ("yellow bile"). Excesses of black bile and yellow bile were thought to produce depression and aggression, respectively, and the Greek names for them gave rise to the English words cholera (from Greek χολή kholē , "bile") and melancholia . In the former of those senses, the same theories explain

819-415: A person's vomit may be green or dark yellow, and very bitter. The bitter and greenish component may be bile or normal digestive juices originating in the stomach. Bile may be forced into the stomach secondary to a weakened valve ( pylorus ), the presence of certain drugs including alcohol , or powerful muscular contractions and duodenal spasms. This is known as biliary reflux . Biliary obstruction refers to

910-410: A population of the bipotential hepatoblasts. Hepatic stellate cells are derived from mesenchyme. After migration of hepatoblasts into the septum transversum mesenchyme, the hepatic architecture begins to be established, with liver sinusoids and bile canaliculi appearing. The liver bud separates into the lobes. The left umbilical vein becomes the ductus venosus and the right vitelline vein becomes

1001-410: A protective benefit against liver cancer for moderate coffee drinkers. A 2017 study revealed that the positive effects of caffeine on the liver were evident regardless of the coffee preparation method. Ursodeoxycholic acid Ursodeoxycholic acid ( UDCA ), also known as ursodiol , is a secondary bile acid , produced in humans and most other species from metabolism by intestinal bacteria. It

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1092-417: A right and a left lobe – and four parts when viewed from below (left, right, caudate , and quadrate lobes ). The falciform ligament makes a superficial division of the liver into a left and right lobe. From below, the two additional lobes are located between the right and left lobes, one in front of the other. A line can be imagined running from the left of the vena cava and all the way forward to divide

1183-409: A role in the production of clotting factors, as well as red blood cell production. Some of the proteins synthesized by the liver include coagulation factors I (fibrinogen), II (prothrombin), V , VII , VIII , IX , X , XI , XII , XIII , as well as protein C , protein S and antithrombin . The liver is a major site of production for thrombopoietin , a glycoprotein hormone that regulates

1274-456: A slain enemy's liver, known as hiemondori ( 冷え物取り ) , was a tradition of the Satsuma people. In regions where bile products are a popular ingredient in traditional medicine , the use of bears in bile-farming has been widespread. This practice has been condemned by activists, and some pharmaceutical companies have developed synthetic (non-ursine) alternatives. Liver The liver

1365-401: Is a "satellite" of hepatitis B virus (it can only infect in the presence of hepatitis B), and co-infects nearly 20 million people with hepatitis B, globally. Hepatic encephalopathy is caused by an accumulation of toxins in the bloodstream that are normally removed by the liver. This condition can result in coma and can prove fatal. Budd–Chiari syndrome is a condition caused by blockage of

1456-485: Is a major metabolic organ exclusively found in vertebrate animals , which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and various other biochemicals necessary for digestion and growth. In humans , it is located in the right upper quadrant of the abdomen , below the diaphragm and mostly shielded by the lower right rib cage . Its other metabolic roles include carbohydrate metabolism ,

1547-463: Is an epimer of chenodeoxycholic acid , which has similar choleretic effects and a wider species distribution. However, CDCA is not as well-tolerated in humans and it does not show immunomodulating or chemoprotective effects. Both are 7-hydroxyl derivatives of deoxycholic acid, but UDCA has the group in the beta instead of the alpha orientation. Among mammals, only bears ( Ursidae ; excluding giant pandas ) produce UDCA at useful amounts (>30%). It

1638-517: Is associated with improved serum liver tests that do not always correlate with improved liver disease status. WHO Drug Information advises against its use in primary sclerosing cholangitis in unapproved doses beyond 13–15 mg/kg/day. UDCA in a dose of 28–30 mg/kg/day increases risk of death and need for liver transplant by 2.3-fold among those with primary sclerosing cholangitis, despite decrease in liver enzymes. UDCA has been used for intrahepatic cholestasis of pregnancy . UDCA lessens itching in

1729-533: Is insufficient evidence to justify routine use of UDCA, especially as there is a lack of available data for long-term outcomes such as death or need for liver transplantation. UDCA has also been in effective in non-alcoholic fatty liver disease , in liver bile duct-paucity syndromes. It is contraindicated in obstruction of biliary tracts such as biliary atresia . It is not effective in liver allograft rejection, and in Graft-versus-host disease involving

1820-450: Is known as the duodenal impression. The inferior surface of the left lobe of the liver presents behind and to the left of the gastric impression. This is moulded over the upper front surface of the stomach, and to the right of this is a rounded eminence, the tuber omentale , which fits into the concavity of the lesser curvature of the stomach and lies in front of the anterior layer of the lesser omentum . Microscopically, each liver lobe

1911-505: Is produced in the bear liver, but the pathway remains unknown. Other vertebrates produce UDCA in much smaller amounts by gut bacteria. CDCA is oxidized into 7-oxo-CDCA then reduced into UDCA. UDCA is most commonly produced from cholic acid (CA) derived from bovine bile, a by-product of the beef industry. The current yield of this semisynthesis is about 30%. The term is from the Latin noun ursus meaning bear, as bear bile contains

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2002-587: Is produced per day in adult human beings. Bile or gall acts to some extent as a surfactant , helping to emulsify the lipids in food. Bile salt anions are hydrophilic on one side and hydrophobic on the other side; consequently, they tend to aggregate around droplets of lipids ( triglycerides and phospholipids ) to form micelles , with the hydrophobic sides towards the fat and hydrophilic sides facing outwards. The hydrophilic sides are negatively charged, and this charge prevents fat droplets coated with bile from re-aggregating into larger fat particles. Ordinarily,

2093-449: Is responsible for the breakdown and excretion of many waste products. It plays a key role in breaking down or modifying toxic substances (e.g., methylation ) and most medicinal products in a process called drug metabolism . This sometimes results in toxication , when the metabolite is more toxic than its precursor. Preferably, the toxins are conjugated to avail excretion in bile or urine. The liver converts ammonia into urea as part of

2184-405: Is seen to be made up of hepatic lobules . The lobules are roughly hexagonal, and consist of plates of hepatocytes , and sinusoids radiating from a central vein towards an imaginary perimeter of interlobular portal triads. The central vein joins to the hepatic vein to carry blood out from the liver. A distinctive component of a lobule is the portal triad , which can be found running along each of

2275-416: Is synthesized in the liver in some species, and was first identified in bile of bears of genus Ursus , from which its name derived. In purified form, it has been used to treat or prevent several diseases of the liver or bile ducts . It is available as a generic medication . UDCA has been used as medical therapy in gallstone disease (cholelithiasis) and for biliary sludge . UDCA helps reduce

2366-405: Is the tube of endoderm that extends out from the foregut into the surrounding mesenchyme. The mesenchyme of septum transversum induces this endoderm to proliferate, to branch, and to form the glandular epithelium of the liver. A portion of the hepatic diverticulum (that region closest to the digestive tube) continues to function as the drainage duct of the liver, and a branch from this duct produces

2457-413: Is uneven and concave. It is covered in peritoneum apart from where it attaches the gallbladder and the porta hepatis. The fossa of gallbladder lies to the right of the quadrate lobe, occupied by the gallbladder with its cystic duct close to the right end of porta hepatis. Several impressions on the surface of the liver accommodate the various adjacent structures and organs. Underneath the right lobe and to

2548-562: Is used to dissolve (cholesterol) gallstones in patients who want an alternative to surgery . There are multiple mechanisms involved in cholestatic liver diseases. Ursodeoxycholic acid has also been shown experimentally to suppress immune response such as immune cell phagocytosis . Prolonged exposure and/or increased quantities of systemic (throughout the body, not just in the digestive system) ursodeoxycholic acid can be toxic. Ursodeoxycholic acid has been shown to exert anti-inflammatory and protective effects in human epithelial cells of

2639-457: Is when gallstone(s) are dislodged from the gallbladder into the cystic duct or common bile duct resulting in a blockage. A blockage of the gallbladder or cystic duct may cause cholecystitis . If the blockage is beyond the confluence of the pancreatic duct, this may cause gallstone pancreatitis . In some instances of biliary obstruction, the bile may become infected by bacteria resulting in ascending cholangitis . In medical theories prevalent in

2730-441: The ampulla of Vater . The liver plays a major role in carbohydrate, protein, amino acid, and lipid metabolism. The liver performs several roles in carbohydrate metabolism. The liver is responsible for the mainstay of protein metabolism , synthesis as well as degradation. All plasma proteins except Gamma-globulins are synthesised in the liver. It is also responsible for a large part of amino acid synthesis . The liver plays

2821-545: The cholesterol saturation of bile and leads to gradual dissolution of cholesterol-rich gallstones. UDCA may be given after bariatric surgery to prevent cholelithiasis, which commonly occurs due to the rapid weight loss producing biliary cholesterol oversaturation and also biliary dyskinesia secondary to hormonal changes. UDCA is used as therapy in primary biliary cholangitis (PBC; previously known as primary biliary cirrhosis) where it can produce an improvement in biomarkers. Meta-analyses have borne out conflicting results on

Bile - Misplaced Pages Continue

2912-432: The falciform ligament and the right and left triangular ligaments . These peritoneal ligaments are not related to the anatomic ligaments in joints, and the right and left triangular ligaments have no known functional importance, though they serve as surface landmarks. The falciform ligament functions to attach the liver to the posterior portion of the anterior body wall. The visceral surface or inferior surface

3003-421: The fibrinogen beta chain protein. Organogenesis , the development of the organs, takes place from the third to the eighth week during embryogenesis . The origins of the liver lie in both the ventral portion of the foregut endoderm (endoderm being one of the three embryonic germ layers ) and the constituents of the adjacent septum transversum mesenchyme . In the human embryo , the hepatic diverticulum

3094-613: The gastrointestinal tract . It has been linked to regulation of immunoregulatory responses by regulation of cytokines , antimicrobial peptides defensins , and take an active part in increased restitution of wound in the colon. Moreover, UDCA's effects has been shown to have exert actions outside the epithelial cells. While some bile acids are known to be colon tumor promoters ( e.g. deoxycholic acid ), others such as ursodeoxycholic acid are thought to be chemopreventive , perhaps by inducing cellular differentiation and/or cellular senescence in colon epithelial cells. Ursodeoxycholic acid

3185-419: The hepatic artery and the portal vein . The hepatic artery carries oxygen-rich blood from the aorta via the celiac trunk , whereas the portal vein carries blood rich in digested nutrients from the entire gastrointestinal tract and also from the spleen and pancreas . These blood vessels subdivide into small capillaries known as liver sinusoids , which then lead to hepatic lobules . Hepatic lobules are

3276-399: The hepatic veins (including thrombosis ) that drain the liver. It presents with the classical triad of abdominal pain, ascites and liver enlargement . Many diseases of the liver are accompanied by jaundice caused by increased levels of bilirubin in the system. The bilirubin results from the breakup of the hemoglobin of dead red blood cells; normally, the liver removes bilirubin from

3367-454: The liver and stored in the gall bladder . When secreted into the intestine, primary bile acids can be metabolized into secondary bile acids by intestinal bacteria. Primary and secondary bile acids help the body digest fats . Ursodeoxycholic acid helps regulate cholesterol by reducing the rate at which the intestine absorbs cholesterol molecules while breaking up micelles containing cholesterol. The drug reduces cholesterol absorption and

3458-428: The ornithine cycle or the urea cycle, and the urea is excreted in the urine. Because the liver is an expandable organ, large quantities of blood can be stored in its blood vessels. Its normal blood volume, including both that in the hepatic veins and that in the hepatic sinuses, is about 450 milliliters, or almost 10 percent of the body's total blood volume. When high pressure in the right atrium causes backpressure in

3549-399: The villi on the intestine walls. After being transferred across the intestinal membrane, the fatty acids reform into triglycerides ( re-esterified ), before being absorbed into the lymphatic system through lacteals . Without bile salts, most of the lipids in food would be excreted in feces, undigested. Since bile increases the absorption of fats, it is an important part of the absorption of

3640-510: The West from classical antiquity to the Middle Ages , the body's health depended on the equilibrium of four "humors" , or vital fluids, two of which related to bile: blood, phlegm , "yellow bile" (choler), and "black bile". These "humors" are believed to have their roots in the appearance of a blood sedimentation test made in open air, which exhibits a dark clot at the bottom ("black bile"),

3731-402: The absence of the liver. As of 2018 , liver transplantation is the only option for complete liver failure . The liver is a dark reddish brown, wedge-shaped organ with two lobes of unequal size and shape. A human liver normally weighs approximately 1.5 kilograms (3.3 pounds) and has a width of about 15 centimetres (6 inches). There is considerable size variation between individuals, with

Bile - Misplaced Pages Continue

3822-504: The absorption of vitamin K from the diet. Some of the bile drains directly into the duodenum, and some is stored in the gallbladder. The liver produces insulin-like growth factor 1 , a polypeptide protein hormone that plays an important role in childhood growth and continues to have anabolic effects in adults. The liver is responsible for the breakdown of insulin and other hormones . The liver breaks down bilirubin via glucuronidation , facilitating its excretion into bile. The liver

3913-455: The blood and constitute plasma proteins and hepatokines . Other liver-specific proteins are certain liver enzymes such as HAO1 and RDH16 , proteins involved in bile synthesis such as BAAT and SLC27A5 , and transporter proteins involved in the metabolism of drugs, such as ABCB11 and SLC2A2 . Examples of highly liver-specific proteins include apolipoprotein A II , coagulation factors F2 and F9 , complement factor related proteins , and

4004-520: The blood and excretes it through bile. Other disorders caused by excessive alcohol consumption are grouped under alcoholic liver diseases and these include alcoholic hepatitis , fatty liver , and cirrhosis . Factors contributing to the development of alcoholic liver diseases are not only the quantity and frequency of alcohol consumption, but can also include gender, genetics, and liver insult. Liver damage can also be caused by drugs , particularly paracetamol and drugs used to treat cancer. A rupture of

4095-467: The centre of each segment are branches of the portal vein, hepatic artery, and bile duct. In the periphery of each segment is vascular outflow through the hepatic veins. The classification system uses the vascular supply in the liver to separate the functional units (numbered I to VIII) with unit 1, the caudate lobe, receiving its supply from both the right and the left branches of the portal vein. It contains one or more hepatic veins which drain directly into

4186-414: The common hepatic duct to form the common bile duct. The biliary system and connective tissue is supplied by the hepatic artery alone. Bile either drains directly into the duodenum via the common bile duct, or is temporarily stored in the gallbladder via the cystic duct. The common bile duct and the pancreatic duct enter the second part of the duodenum together at the hepatopancreatic ampulla, also known as

4277-446: The derivation of the English word bilious from bile , the meaning of gall in English as "exasperation" or "impudence", and the Latin word cholera , derived from the Greek kholé , which was passed along into some Romance languages as words connoting anger, such as colère (French) and cólera (Spanish). Soap can be mixed with bile from mammals, such as ox gall . This mixture, called bile soap or gall soap, can be applied to textiles

4368-418: The edge of the liver lobule, where they merge to form bile ducts. Within the liver, these ducts are termed intrahepatic bile ducts, and once they exit the liver, they are considered extrahepatic. The intrahepatic ducts eventually drain into the right and left hepatic ducts, which exit the liver at the transverse fissure , and merge to form the common hepatic duct. The cystic duct from the gallbladder joins with

4459-437: The eighth segment is only visible in the visceral view. On the diaphragmatic surface, apart from a triangular bare area where it connects to the diaphragm, the liver is covered by a thin, double-layered membrane, the peritoneum , that helps to reduce friction against other organs. This surface covers the convex shape of the two lobes where it accommodates the shape of the diaphragm. The peritoneum folds back on itself to form

4550-564: The family Herpesviridae such as the herpes simplex virus . Chronic (rather than acute) infection with hepatitis B virus or hepatitis C virus is the main cause of liver cancer . Globally, about 248 million individuals are chronically infected with hepatitis B (with 843,724 in the U.S.), and 142 million are chronically infected with hepatitis C (with 2.7 million in the U.S.). Globally there are about 114 million and 20 million cases of hepatitis A and hepatitis E respectively, but these generally resolve and do not become chronic. Hepatitis D virus

4641-448: The fat-soluble substances, such as the vitamins A , D , E , and K . Besides its digestive function, bile serves also as the route of excretion for bilirubin, a byproduct of red blood cells recycled by the liver. Bilirubin derives from hemoglobin by glucuronidation . Bile tends to be alkaline on average. The pH of common duct bile (7.50 to 8.05) is higher than that of the corresponding gallbladder bile (6.80 to 7.65). Bile in

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4732-448: The functional lobes are further divided into a total of eight subsegments based on a transverse plane through the bifurcation of the main portal vein. The caudate lobe is a separate structure that receives blood flow from both the right- and left-sided vascular branches. The Couinaud classification divides the liver into eight functionally independent liver segments. Each segment has its own vascular inflow, outflow and biliary drainage. In

4823-411: The functional units of the liver. Each lobule is made up of millions of hepatic cells (hepatocytes), which are the basic metabolic cells. The lobules are held together by a fine, dense, irregular, fibroelastic connective tissue layer extending from the fibrous capsule covering the entire liver known as Glisson's capsule after British doctor Francis Glisson . This tissue extends into the structure of

4914-485: The functions of a mature hepatocyte, and eventually mature hepatocytes appear as highly polarized epithelial cells with abundant glycogen accumulation. In the adult liver, hepatocytes are not equivalent, with position along the portocentrovenular axis within a liver lobule dictating expression of metabolic genes involved in drug metabolism, carbohydrate metabolism , ammonia detoxification, and bile production and secretion. WNT/β-catenin has now been identified to be playing

5005-462: The gallbladder becomes more acidic the longer a person goes without eating, though resting slows this fall in pH. As an alkali, it also has the function of neutralizing excess stomach acid before it enters the duodenum, the first section of the small intestine . Bile salts also act as bactericides , destroying many of the microbes that may be present in the food. In the absence of bile, fats become indigestible and are instead excreted in feces ,

5096-412: The gallbladder. Besides signals from the septum transversum mesenchyme, fibroblast growth factor from the developing heart also contributes to hepatic competence, along with retinoic acid emanating from the lateral plate mesoderm . The hepatic endodermal cells undergo a morphological transition from columnar to pseudostratified resulting in thickening into the early liver bud . Their expansion forms

5187-405: The imaginary plane, Cantlie's line, joining the gallbladder fossa to the inferior vena cava . The plane separates the liver into the true right and left lobes. The middle hepatic vein also demarcates the true right and left lobes. The right lobe is further divided into an anterior and posterior segment by the right hepatic vein. The left lobe is divided into the medial and lateral segments by

5278-437: The inferior vena cava, allowing placental blood to bypass the liver. In the fetus, the liver does not perform the normal digestive processes and filtration of the infant liver because nutrients are received directly from the mother via the placenta . The fetal liver releases some blood stem cells that migrate to the fetal thymus , creating the T cells (or T lymphocytes). After birth, the formation of blood stem cells shifts to

5369-463: The inferior vena cava. The remainder of the units (II to VIII) are numbered in a clockwise fashion: About 20,000 protein coding genes are expressed in human cells and 60% of these genes are expressed in a normal, adult liver. Over 400 genes are more specifically expressed in the liver, with some 150 genes highly specific for liver tissue. A large fraction of the corresponding liver-specific proteins are mainly expressed in hepatocytes and secreted into

5460-468: The large intestine. The cholesterol contained in bile will occasionally accrete into lumps in the gallbladder, forming gallstones . Cholesterol gallstones are generally treated through surgical removal of the gallbladder. However, they can sometimes be dissolved by increasing the concentration of certain naturally occurring bile acids, such as chenodeoxycholic acid and ursodeoxycholic acid . On an empty stomach – after repeated vomiting , for example –

5551-423: The left hepatic vein. The hilum of the liver is described in terms of three plates that contain the bile ducts and blood vessels. The contents of the whole plate system are surrounded by a sheath. The three plates are the hilar plate , the cystic plate and the umbilical plate and the plate system is the site of the many anatomical variations to be found in the liver. In the widely used Couinaud system,

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5642-445: The liver and drain into the inferior vena cava. The biliary tract is derived from the branches of the bile ducts. The biliary tract, also known as the biliary tree, is the path by which bile is secreted by the liver then transported to the first part of the small intestine, the duodenum . The bile produced in the liver is collected in bile canaliculi , small grooves between the faces of adjacent hepatocytes. The canaliculi radiate to

5733-494: The liver and gallbladder into two halves. This line is called Cantlie's line . Other anatomical landmarks include the ligamentum venosum and the round ligament of the liver , which further divide the left side of the liver in two sections. An important anatomical landmark, the porta hepatis , divides this left portion into four segments, which can be numbered starting at the caudate lobe as I in an anticlockwise manner. From this parietal view, seven segments can be seen, because

5824-492: The liver are carried out by the liver cells or hepatocytes. The liver is thought to be responsible for up to 500 separate functions, usually in combination with other systems and organs. Currently, no artificial organ or device is capable of reproducing all the functions of the liver. Some functions can be carried out by liver dialysis , an experimental treatment for liver failure . The liver also accounts for about 20% of resting total body oxygen consumption. The liver receives

5915-494: The liver by accompanying the blood vessels, ducts, and nerves at the hepatic hilum. The whole surface of the liver, except for the bare area , is covered in a serous coat derived from the peritoneum , and this firmly adheres to the inner Glisson's capsule. Terminology related to the liver often starts in hepat- from ἡπατο-, from the Greek word for liver. The liver is grossly divided into two parts when viewed from above –

6006-417: The liver can be caused by a liver shot used in combat sports. Primary biliary cholangitis is an autoimmune disease of the liver. It is marked by slow progressive destruction of the small bile ducts of the liver, with the intralobular ducts ( Canals of Hering ) affected early in the disease. When these ducts are damaged, bile and other toxins build up in the liver ( cholestasis ) and over time damages

6097-490: The liver in response to injury or inflammation. The most common chronic liver disease is nonalcoholic fatty liver disease , which affects an estimated one-third of the world population. Hepatitis is a common condition of inflammation of the liver. The most usual cause of this is viral , and the most common of these infections are hepatitis A , B , C , D , and E . Some of these infections are sexually transmitted . Inflammation can also be caused by other viruses in

6188-404: The liver is the umbilical vein, which supplies nutrients to the growing fetus. The umbilical vein enters the abdomen at the umbilicus and passes upward along the free margin of the falciform ligament of the liver to the inferior surface of the liver. There, it joins with the left branch of the portal vein. The ductus venosus carries blood from the left portal vein to the left hepatic vein and then to

6279-419: The liver only produces symptoms after extensive damage. Hepatomegaly refers to an enlarged liver and can be due to many causes. It can be palpated in a liver span measurement. Consuming caffeine regularly may help safeguard individuals from liver cirrhosis . Additionally, it has been shown to slow the advancement of liver disease in those already affected, lower the risk of liver fibrosis, and provide

6370-584: The liver tissue in combination with ongoing immune related damage. This can lead to scarring ( fibrosis ) and cirrhosis . Cirrhosis increases the resistance to blood flow in the liver, and can result in portal hypertension . Congested anastomoses between the portal venous system and the systemic circulation, can be a subsequent condition. There are also many pediatric liver diseases, including biliary atresia , alpha-1 antitrypsin deficiency , alagille syndrome , progressive familial intrahepatic cholestasis , Langerhans cell histiocytosis and hepatic hemangioma

6461-467: The liver volume is occupied by parenchymal hepatocytes. Nonparenchymal cells constitute 40% of the total number of liver cells but only 6.5% of its volume. The liver sinusoids are lined with two types of cell, sinusoidal endothelial cells , and phagocytic Kupffer cells . Hepatic stellate cells are nonparenchymal cells found in the perisinusoidal space , between a sinusoid and a hepatocyte. Additionally, intrahepatic lymphocytes are often present in

6552-444: The liver's oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries. The hepatic artery also has both alpha- and beta-adrenergic receptors; therefore, flow through the artery is controlled, in part, by the splanchnic nerves of the autonomic nervous system. Blood flows through the liver sinusoids and empties into the central vein of each lobule. The central veins coalesce into hepatic veins, which leave

6643-421: The liver, the liver expands, and 0.5 to 1 liter of extra blood is occasionally stored in the hepatic veins and sinuses. This occurs especially in cardiac failure with peripheral congestion. Thus, in effect, the liver is a large, expandable, venous organ capable of acting as a valuable blood reservoir in times of excess blood volume and capable of supplying extra blood in times of diminished blood volume. Because

6734-545: The liver. Diarrhea was the most frequent adverse event seen in trial of UDCA in gallstone dissolution, occurring in 2 to 9%, which is less frequent than with chenodeoxycholic acid therapy. Bacterial conversion of UDCA to chenodeoxycholic acid may be the mechanism for this side effect. Right upper quadrant abdominal pain and exacerbation of pruritus was occasionally reported in trials in patients with PBC. Additional symptoms may include bloating, weight gain, and occasionally, thinning of hair. Primary bile acids are produced by

6825-429: The lobule's corners. The portal triad consists of the hepatic artery, the portal vein, and the common bile duct. The triad may be seen on a liver ultrasound, as a Mickey Mouse sign with the portal vein as the head, and the hepatic artery, and the common bile duct as the ears. Histology , the study of microscopic anatomy, shows two major types of liver cell: parenchymal cells and nonparenchymal cells. About 70–85% of

6916-552: The lymph formed in the body under resting conditions arises in the liver. The liver is a vital organ and supports almost every other organ in the body. Because of its strategic location and multidimensional functions, the liver is prone to many diseases. The bare area of the liver is a site that is vulnerable to the passing of infection from the abdominal cavity to the thoracic cavity . Liver diseases may be diagnosed by liver function tests –blood tests that can identify various markers. For example, acute-phase reactants are produced by

7007-416: The micelles in the duodenum have a diameter around 1–50  μm in humans. The dispersion of food fat into micelles provides a greatly increased surface area for the action of the enzyme pancreatic lipase , which digests the triglycerides, and is able to reach the fatty core through gaps between the bile salts. A triglyceride is broken down into two fatty acids and a monoglyceride , which are absorbed by

7098-451: The mortality benefit. However analyses that exclude trials of short duration (i.e. < 2 years) have demonstrated a survival benefit and are generally considered more clinically relevant. A Cochrane systematic review in 2012 found no significant benefit in reducing mortality, the rate of liver transplantation, pruritus or fatigue. Ursodiol and obeticholic acid are FDA-approved for the treatment of primary biliary cholangitis. UDCA use

7189-548: The mother and may reduce the number of preterm births. Effects on fetal distress and other adverse outcomes are unlikely to be great. UDCA use is not licensed in children, as its safety and effectiveness have not been established. Evidence is accumulating that ursodeoxycholic acid is ineffective, unsafe and its use is associated with significant risk of morbidity and mortality in neonatal hepatitis and neonatal cholestasis. UDCA has been suggested to be an adequate treatment of bile reflux gastritis . In cystic fibrosis there

7280-416: The organ's total number of functions vary, but is generally cited as being around 500. For this reason, the liver has sometimes been described as the body's chemical factory . It is not known how to compensate for the absence of liver function in the long term, although liver dialysis techniques can be used in the short term. Artificial livers have not been developed to promote long-term replacement in

7371-429: The pores in the hepatic sinusoids are very permeable and allow ready passage of both fluid and proteins into the perisinusoidal space , the lymph draining from the liver usually has a protein concentration of about 6 g/dl, which is only slightly less than the protein concentration of plasma. Also, the high permeability of the liver sinusoid epithelium allows large quantities of lymph to form. Therefore, about half of all

7462-753: The portal vein. The expanding liver bud is colonized by hematopoietic cells . The bipotential hepatoblasts begin differentiating into biliary epithelial cells and hepatocytes. The biliary epithelial cells differentiate from hepatoblasts around portal veins, first producing a monolayer, and then a bilayer of cuboidal cells. In ductal plate, focal dilations emerge at points in the bilayer, become surrounded by portal mesenchyme, and undergo tubulogenesis into intrahepatic bile ducts. Hepatoblasts not adjacent to portal veins instead differentiate into hepatocytes and arrange into cords lined by sinusoidal epithelial cells and bile canaliculi. Once hepatoblasts are specified into hepatocytes and undergo further expansion, they begin acquiring

7553-402: The production of hormones , conversion and storage of nutrients such as glucose and glycogen , and the decomposition of red blood cells . The liver is also an accessory digestive organ that produces bile , an alkaline fluid containing cholesterol and bile acids , which emulsifies and aids the breakdown of dietary fat . The gallbladder , a small hollow pouch that sits just under

7644-400: The production of platelets by the bone marrow. The liver plays several roles in lipid metabolism: it performs cholesterol synthesis, lipogenesis , and the production of triglycerides , and a bulk of the body's lipoproteins are synthesized in the liver. The liver plays a key role in digestion, as it produces and excretes bile (a yellowish liquid) required for emulsifying fats and help

7735-412: The red bone marrow . After 2–5 days, the umbilical vein and ductus venosus are obliterated; the former becomes the round ligament of liver and the latter becomes the ligamentum venosum. In the disorders of cirrhosis and portal hypertension , the umbilical vein can open up again. Unlike eutherian mammals, in marsupials the liver remains haematopoietic well after birth. The various functions of

7826-444: The right lobe of liver, stores and concentrates the bile produced by the liver, which is later excreted to the duodenum to help with digestion . The liver's highly specialized tissue , consisting mostly of hepatocytes , regulates a wide variety of high-volume biochemical reactions, including the synthesis and breakdown of small and complex organic molecules, many of which are necessary for normal vital functions. Estimates regarding

7917-415: The right of the fossa , between the bare area and the caudate lobe, and immediately above the renal impression. The greater part of the suprarenal impression is devoid of peritoneum and it lodges the right suprarenal gland. Medial to the renal impression is a third and slightly marked impression, lying between it and the neck of the gall bladder. This is caused by the descending portion of the duodenum, and

8008-410: The right of the gallbladder fossa are two impressions, one behind the other and separated by a ridge. The one in front is a shallow colic impression, formed by the hepatic flexure and the one behind is a deeper renal impression accommodating part of the right kidney and part of the suprarenal gland . The suprarenal impression is a small, triangular, depressed area on the liver. It is located close to

8099-416: The sinusoidal lumen. The central area or hepatic hilum , includes the opening known as the porta hepatis which carries the common bile duct and common hepatic artery , and the opening for the portal vein. The duct, vein, and artery divide into left and right branches, and the areas of the liver supplied by these branches constitute the functional left and right lobes. The functional lobes are separated by

8190-437: The standard reference range for men being 970–1,860 grams (2.14–4.10 lb) and for women 600–1,770 g (1.32–3.90 lb). It is both the heaviest internal organ and the largest gland in the human body. It is located in the right upper quadrant of the abdominal cavity , resting just below the diaphragm, to the right of the stomach, and overlying the gallbladder . The liver is connected to two large blood vessels :

8281-427: The substance. Ursodeoxycholic acid can be chemically synthesized and is marketed under multiple trade names, including Ursetor, Udikast, Actibile, Actigall, Biliver, Deursil, Egyurso, Heptiza 300/150, Stener, Udcasid, Udiliv, Udinorm, Udoxyl, Urso, Urso Forte, Ursocol, Ursoliv, Ursofalk, Ursosan, Ursoserinox, Udimarin, and Ursonova. Bear bile, a natural source of UDCA, is used in traditional Chinese medicine since

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