WebMD's Liver Anatomy Page provides detailed images, definitions, and information about the liver. Learn about its function, parts, location on. Your liver does all kinds of work that's critical to your health. It helps break down food, clean your blood, make proteins, and store energy. Liver disease can be inherited (genetic) or caused by a variety of factors that damage the liver, such as viruses and alcohol use. Obesity is also.
Scar tissue cannot do the work that healthy liver tissue can. Moreover, scar tissue can keep blood from flowing through your liver. As more scar tissue builds up, your liver may not work as well as it once did. Or, the healthy part of your liver has to work harder to make up for the scarred part.
Cirrhosis is the scarring of the liver — hard scar tissue replaces soft healthy tissue. As cirrhosis becomes worse, the liver will have less healthy tissue.
If cirrhosis is not treated, the liver will fail and will not be able to work well or at all. Cirrhosis can lead to a number of complications, including liver cancer. In some people, the symptoms of cirrhosis may be the first signs of liver disease. It may be possible to stop or slow the liver damage.
It is important to protect the healthy liver tissue you have left. End-Stage Liver Disease includes a subgroup of patients with cirrhosis who have signs of decompensation that is generally irreversible with medical management other than transplant. Decompensation includes hepatic encephalopathy, variceal bleed, kidney impairment, ascites, lung issues. The decompensated liver disease allows these patients to be prioritized on the transplant list.
Cancer that starts in the liver is called primary liver cancer. Cirrhosis and hepatitis B are leading risk factors for primary liver cancer. But cancer can develop in the liver at any stage in the progression of liver disease. Liver failure means that your liver is losing or has lost all of its function. It is a life-threatening condition that demands urgent medical care. The first symptoms of liver failure are often nausea, loss of appetite, fatigue, and diarrhea. Because these symptoms can have any number of causes, it may be hard to tell that the liver is failing.
But as liver failure progresses, the symptoms become more serious. The patient may become confused and disoriented, and extremely sleepy. There is a risk of coma and death. Immediate treatment is needed. The medical team will try to save whatever part of the liver that still works. If this is not possible, the only option may be a liver transplant. Liver failure is a life-threatening condition that demands urgent medical care.
When liver failure occurs as a result of cirrhosis, it usually means that the liver has been failing gradually for some time, possibly for years. Chronic liver failure can also be caused by malnutrition. More rarely, liver failure can occur suddenly, in as little as 48 hours.
This is called acute liver failure and is usually a reaction to poisoning or a medication overdose. Cirrhosis, liver cancer, and liver failure are serious conditions that can threaten your life. Once you have reached these stages of liver disease, your treatment options may be very limited.
If you are treated successfully at these stages, your liver may have a chance to heal itself and recover. Talk to your doctor about liver disease. The central veins coalesce into hepatic veins, which leave 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 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 the common hepatic duct to form the common bile duct. 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 the ampulla of Vater.
The liver performs several roles in carbohydrate metabolism: The liver synthesizes and stores around g of glycogen via glycogenesis , the formation of glycogen from glucose. When needed, the liver releases glucose into the blood by performing glycogenolysis , the breakdown of glycogen into glucose. Adipose and liver cells produce glycerol by breakdown of fat , which the liver uses for gluconeogenesis.
The liver is responsible for the mainstay of protein metabolism , synthesis as well as degradation. It is also responsible for a large part of amino acid synthesis. The liver plays a role in the production of clotting factors, as well as red blood cell production. In the first trimester fetus , the liver is the main site of red blood cell production. By the 32nd week of gestation , the bone marrow has almost completely taken over that task.
The liver is a major site of production for thrombopoietin , a glycoprotein hormone that regulates the production of platelets by the bone marrow. The liver plays several roles in lipid metabolism: The liver plays a key role in digestion, as it produces and excretes bile a yellowish liquid required for emulsifying fats and help 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 also 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 is responsible for the breakdown and excretion of many waste products. It plays a key role in breaking down or modifying toxic substances e. 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 breaks down ammonia into urea as part of the urea cycle , and the urea is excreted in the urine. The oxidative capacity of the liver decreases with aging and therefore any medications that require oxidation for instance, benzodiazepines are more likely to accumulate to toxic levels.
However, medications with shorter half-lives , such as lorazepam and oxazepam , are preferred in most cases when benzodiazepines are required in regard to geriatric medicine. 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 also prone to many diseases.
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 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 there are about million and 20 million cases of hepatitis A  and hepatitis E  respectively, but these generally resolve, and do not become chronic. Hepatitis D virus is a "satellite" of hepatitis B virus 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. 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 the liver can be caused by a liver shot used in combat sports. Budd—Chiari syndrome is a condition caused by blockage of the hepatic veins including thrombosis that drain the liver.
It presents with the classical triad of abdominal pain, ascites and liver enlargement. Primary biliary cholangitis is an autoimmune disease of the liver. 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. 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 the blood and excretes it through bile. 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 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, 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. Liver diseases may be diagnosed by liver function tests —blood tests that can identify various markers. For example, acute-phase reactants are produced by the liver in response to injury or inflammation. The diagnosis of liver disease is made by liver function tests , groups of blood tests , that can readily show the extent of liver damage.
If infection is suspected, then other serological tests will be carried out. A physical examination of the liver can only reveal its size and any tenderness, and some form of imaging such as an ultrasound or CT scan may also be needed. This procedure may be helped by a sonographer providing ultrasound guidance to an interventional radiologist. Axial CT image showing anomalous hepatic veins coursing on the subcapsular anterior surface of the liver.
Maximum intensity projection MIP CT image as viewed anteriorly showing the anomalous hepatic veins coursing on the anterior surface of the liver. This contrasts with true regeneration where both original function and form are restored. In some other species, such as fish, the liver undergoes true regeneration by restoring both shape and size of the organ.
This is predominantly due to the hepatocytes re-entering the cell cycle. That is, the hepatocytes go from the quiescent G0 phase to the G1 phase and undergo mitosis. This process is activated by the p75 receptors. These cells can differentiate into either hepatocytes or cholangiocytes. Cholangiocytes are the epithelial lining cells of the bile ducts. Research is being carried out on the use of stem cells for the generation of an artificial liver.
Scientific and medical works about liver regeneration often refer to the Greek Titan Prometheus who was chained to a rock in the Caucasus where, each day, his liver was devoured by an eagle, only to grow back each night.
Human liver transplants were first performed by Thomas Starzl in the United States and Roy Calne in Cambridge , England in and , respectively. Liver transplantation is the only option for those with irreversible liver failure.
Most transplants are done for chronic liver diseases leading to cirrhosis , such as chronic hepatitis C , alcoholism , and autoimmune hepatitis.
Less commonly, liver transplantation is done for fulminant hepatic failure , in which liver failure occurs over days to weeks. Liver allografts for transplant usually come from donors who have died from fatal brain injury. Living donor liver transplantation is a technique in which a portion of a living person's liver is removed hepatectomy and used to replace the entire liver of the recipient. This was first performed in for pediatric liver transplantation.
Only 20 percent of an adult's liver Couinaud segments 2 and 3 is needed to serve as a liver allograft for an infant or small child.
More recently, [ when? Due to the ability of the liver to regenerate , both the donor and recipient end up with normal liver function if all goes well. This procedure is more controversial, as it entails performing a much larger operation on the donor, and indeed there have been at least two donor deaths out of the first several hundred cases. A recent publication has addressed the problem of donor mortality, and at least 14 cases have been found.
With the recent advances of noninvasive imaging, living liver donors usually have to undergo imaging examinations for liver anatomy to decide if the anatomy is feasible for donation.
MDCT is good in vascular anatomy and volumetry. MRI is used for biliary tree anatomy. Donors with very unusual vascular anatomy, which makes them unsuitable for donation, could be screened out to avoid unnecessary operations.
Phase contrast CT image. Contrast is perfusing the right liver but not the left due to a left portal vein thrombus. Some cultures regard the liver as the seat of the soul. In Greek mythology , the gods punished Prometheus for revealing fire to humans by chaining him to a rock where a vulture or an eagle would peck out his liver, which would regenerate overnight. The liver is the only human internal organ that actually can regenerate itself to a significant extent. Many ancient peoples of the Near East and Mediterranean areas practiced a type of divination called haruspicy or hepatomancy , where they tried to obtain information by examining the livers of sheep and other animals.
In Plato, and in later physiology, the liver was thought to be the seat of the darkest emotions specifically wrath, jealousy and greed which drive men to action. In Persian slang, jigar is used as an adjective for any object which is desirable, especially women. In the Zulu language , the word for liver isibindi is the same as the word for courage.
The legend of Liver-Eating Johnson died says that he would cut out and eat the liver of each man killed after dinner. There are narrations that suggest that Hind "tasted" rather than ate the liver of Hamza. On November 26, , the city of Ferrol , Spain, inaugurated what is believed [ by whom? The then-mayor, Jaime Quintanilla, also happened to be a doctor, and thought it appropriate to promote the monument. A plaque reads in Galician , free translation: By helping it on this duty, you are doing a great job.
We are grateful for it". Humans commonly eat the livers of mammals, fowl , and fish as food. Domestic pig , ox , lamb , calf , chicken , and goose livers are widely available from butchers and supermarkets. Liver can be baked, boiled, broiled, fried, stir-fried , or eaten raw asbeh nayeh or sawda naye in Lebanese cuisine , or liver sashimi in Japanese cuisine. In many preparations, pieces of liver are combined with pieces of meat or kidneys, as in the various forms of Middle Eastern mixed grill e.
Liver sausages such as Braunschweiger and liverwurst are also a valued meal. Liver sausages may also be used as spreads. A traditional South African delicacy, skilpadjies , is made of minced lamb's liver wrapped in netvet caul fat , and grilled over an open fire. Animal livers are rich in iron, vitamin A and vitamin B 12 ; and cod liver oil is commonly used as a dietary supplement.
Traditionally, some fish livers were valued as food, especially the stingray liver. It was used to prepare delicacies, such as poached skate liver on toast in England, as well as the beignets de foie de raie and foie de raie en croute in French cuisine. It is said that a person, once he has drunk umm nyolokh , will return to giraffe again and again. Humr, being Mahdists , are strict abstainers [ from alcohol ] and a Humrawi is never drunk sakran on liquor or beer.
But he uses this word to describe the effects which umm nyolokh has upon him. Cunnison's remarkable account of an apparently psychoactive mammal found its way from a somewhat obscure scientific paper into more mainstream literature through a conversation between Dr. Wendy James of the Institute of Social and Cultural Anthropology at the University of Oxford and specialist on the use of hallucinogens and intoxicants in society Richard Rudgley , who considered its implications in his popular work The Encyclopedia of Psychoactive Substances.
Rudgley hypothesises that the presence of the hallucinogenic compound DMT might account for the putative intoxicating properties of umm nyolokh. Cunnison himself, on the other hand, had found it hard fully to believe in the literal truth of the Humr's assertion that their drink was intoxicating:. I can only assume that there is no intoxicating substance in the drink and that the effect it produces is simply a matter of convention, although it may be brought about subconsciously.
The study of entheogens in general - including entheogens of animal origin e. Certain Tungusic peoples formerly prepared a type of arrow poison from rotting animal livers, which was, in later times, also applied to bullets.
Russian anthropologist Sergei Mikhailovich Shirokogorov , revered as one of the greatest scholars of Tungusic studies, notes that:. Formerly the using of poisoned arrows was common. I am not competent to judge as to the chemical conditions of production of poison which is not destroyed by the heat of explosion.
However, the Tungus themselves compare this method [ of poisoning ammunition ] with the poisoning of arrows. The liver is found in all vertebrates , and is typically the largest visceral internal organ. Its form varies considerably in different species, and is largely determined by the shape and arrangement of the surrounding organs. Nonetheless, in most species it is divided into right and left lobes; exceptions to this general rule include snakes , where the shape of the body necessitates a simple cigar-like form.
The internal structure of the liver is broadly similar in all vertebrates. An organ sometimes referred to as a liver is found associated with the digestive tract of the primitive chordate Amphioxus. Although it performs many functions of a liver, it is not considered a true liver but a homolog of the vertebrate liver.
From Wikipedia, the free encyclopedia. For other uses, see Liver disambiguation. The human liver is located in the upper right abdomen. Proteins produced and secreted by the liver. Portal venous anatomy contraindicated for liver donation.
Surgical Clinics of North America. Principles of Anatomy and Physiology 12th ed.
Liver Function Tests
There is more to compromised liver health than pain and a yellow Here are some sneaky signs that your liver might not be functioning as it. This organ is vital to the body's metabolic functions and immune system. Without a functioning liver, a person cannot survive. The liver's position. Liver function tests, also known as liver chemistries, help determine the health of your liver by measuring the levels of proteins, liver enzymes.