Any of the large, polygonal-shaped cells in the liver. They are epithelial cells.
Hepatocytes are the major functional component of the liver. They make up 70-80% of the mass of the liver. 1/2 a hair thickness, live for about 6 months, divide quite slowly, power station of the liver, make bile, store vitamins and fats, make important proteins, secrete glucose, and are also involved in detoxification and metabolism.

They are parenchyma cells arranged in plates that anastomose with one another. Most of them have a single nucleus although binucleate cells are also not uncommon. They also have abundant rough and smooth endoplasmic reticulum, as well as stacks of Golgi membrane, which are necessary for their function. 

They perform various functions such as synthesis of proteins and lipids for secretion, storage and transformation of carbohydrates (e.g. glycogen into glucose), synthesis of cholesterol, bile salts and phospholipids, and detoxification, modification and excretion of exogenous and endogenous substances. 

 Word origin: Greek hépat-, s. of hêpar liver + New Latin -cyta, from Greek kutos, hollow vessel. 

Synonym: liver cell.
See also: liver.
Source:https://www.biology-online.org/dictionary/Hepatocyte 

[TA]

1. a quadrangular area of the visceral surface of the liver, bounded by umbilical fissure on the left side, the fossa for the gallbladder on the right side, the porta hepatis superiorly and posteriorly, and the inferior border of the liver anteriorly and inferiorly; it is called a "lobe" by tradition, but is only a surface feature.

2. Synonym(s): quadrangular lobule

3. Synonym(s): precuneus

Synonym(s): lobus quadratus hepatis
Source: https://medical-dictionary.thefreedictionary.com/quadrate+lobe+of+liver

 The venous blood from the GI tract drains into the superior and inferior mesenteric veins; these two vessels are then joined by the splenic vein just posterior to the neck of the pancreas to form the portal vein. This then splits to form the right and left branches, each supplying about half of the liver.
 On entering the liver, the blood drains into the hepatic sinusoids, where it is screened by specialised macrophages (Kupffer cells) to remove any pathogens that manage to get past the GI defences. The plasma is filtered through the endothelial lining of the sinusoids and bathes the hepatocytes; these cells contain vast numbers of enzymes capable of braking down and metabolising most of what has been absorbed.

 The portal venous blood contains all of the products of digestion absorbed from the GI tract, so all useful and non-useful products are processed in the liver before being either released back into the hepatic veins which join the inferior vena cava just inferior to the diaphragm, or stored in the liver for later use.

Source:https://www.le.ac.uk/pa/teach/va/anatomy/case5/5_3.html

It is approximately three to four inches in length and is usually formed by the merging of the superior mesenteric and splenic veins behind the upper edge of the head of the pancreas. In some individuals, the inferior mesenteric vein may enter this intersection instead. 

In most people, the portal vein splits into left and right veins before entering the liver. The right vein then branches off into anterior and superior veins.

The portal vein supplies approximately 75 percent of blood flow to the liver. The portal vein is not a true vein, which means it does not drain into the heart. Instead, it brings nutrient-rich blood to the liver from the gastrointestinal tract and spleen. Once there, the liver can process the nutrients from the blood and filter out any toxic substances it contains before the blood goes back into general circulation.

 Abnormally high blood pressure in the portal vein is known as portal hypertension. The condition may cause the growth of new blood vessels that bypass the liver, which can result in the circulation of unfiltered blood throughout the body. Portal hypertension is one of the potential serious complications of liver cirrhosis, which is a condition where normal liver tissue is replaced with scar tissue.

Source: https://www.healthline.com/human-body-maps/portal-vein

The common hepatic artery splits into the proper hepatic artery and the gastroduodenal artery. The proper hepatic artery enters the porta hepatis where it splits into the left and right hepatic arteries that supply the liver.

The gastroduodenal branch of the common hepatic artery passes behind the duodenum and divides into the right gastroepiploic artery and the superior pancreaticoduodenal artery. The right gastroepiploic artery runs along the curve of the stomach and connects with the left gastroepiploic artery. These arteries supply blood to the stomach and greater omentum, a folded membrane that attaches the stomach to the transverse colon. The right gastroepiploic artery is often used as a graft for coronary artery bypasses.

The superior pancreaticoduodenal artery divides into anterior and posterior branches that circle the head of the pancreas and connect with the inferior pancreaticoduodenal artery. These arteries supply blood to the pancreas and duodenum.

 The right hepatic artery usually branches off the proper hepatic artery or the left hepatic artery but this varies in different people. The cystic artery originates from the right hepatic artery and supplies blood to the gallbladder.

Source:https://www.healthline.com/human-body-maps/common-hepatic-artery 

PSC is an uncommon chronic liver disease in which the bile ducts inside and outside the liver progressively decrease in size due to inflammation and scarring (fibrosis). The disease may occur alone, but frequently is associated with inflammatory diseases of the colon, especially chronic ulcerative colitis.

Bile ducts are tubes which carry bile (a greenish yellow liquid made by the liver) into the upper part of the bowel. Bile acts as a detergent breaking up fat from the food we eat into small droplets that can then be absorbed into the body. It also enables the body to absorb vitamins A, D, E and K from our diet.

As a consequence, bile that is normally carried by these ducts accumulates within the liver. This blockage to bile flow also causes damage to liver cells causing inflammation and scarring. Over many years the scarring can affect the whole liver and the system of bile ducts. A damaged liver can re-grow without scarring but in PSC, the re-growth goes wrong and the healing process is incomplete. The combination of scar tissue and irregular growth is known as cirrhosis.

Source: https://www.britishlivertrust.org.uk/liver-information/liver-conditions/primary-sclerosing-cholangitis/

Liver functions include:

Producing quick energy
  One of the liver’s most important functions is to break down food and convert it into energy. Carbohydrates, such as bread and potatoes, are broken down to glucose and stored mainly in the liver and muscles as glycogen. When energy is required in an emergency the liver rapidly converts its store of glycogen back into glucose ready for use.

Your liver also helps the body to get rid of waste. Waste products which are not excreted by your kidneys are removed from the blood by the liver. Some of them pass into the duodenum and then into the bowel via the bile ducts.

People with liver damage may sometimes lose the ability to control glucose concentration in the blood and need a regular supply of sugar.

Fighting infections
  Your liver plays a vital role in fighting infections, particularly infections arising in the bowel. It does this by mobilising part of your body’s defence mechanism called the macrophage system. The liver contains over half of the body’s supply of macrophages, known as Kuppfer cells, which literally destroy any bacteria that they come into contact with. If the liver is damaged in any way its ability to fight infections is impaired.

Symptoms of liver damage can be difficult to spot as they are not always obvious – they can include tiredness, nausea and itching. NHS choices website has information about the signs, symptoms and causes of liver disease.

https://www.britishlivertrust.org.uk/liver-information/