Liver

Basic facts

Lies mainly in right hypochondrium and epigastrium, extending into part of left hypochondrium

Increases in size rapidly, achieving maximum size at the age of 18

Gradual decrease in size from middle age onwards

Weight – infants 5% of total body weight

adults- 2% Wedge shaped- shape determined by

the form of upper abdominal cavity into which it grows

Reddish brown colour – varies according to fat content

Obesity is commonest factor leading to increase in fat content [steatosis]

Increased fat – yellow tinge Soft to firm consistency – partly

dependant on blood volume in liver and fat content

Surfaces

Diaphragmatic Visceral

Relations

Superiorly

Right dome of diaphragm Heart Left dome of diaphragm [partly]

Anteriorly

Anterior attachment of diaphragmRight pleuraRight 6th- 1oth ribs and their costal

cartilagesLeft 7th and 8th costal cartilages

Right

Right dome of diaphragm Right lung and basal pleura Costophrenic recess 9th and 10th ribs

Visceral surface

Relations

Gall bladder Oesophagus Fundus of stomach Pylorus 1st part of duodenum

Hepatic flexure of colon Right suprarenal gland Right kidney `

Hepatic segments

Blood supply

Dual- venous blood via portal vein and

arterial supply by hepatic artery: both vessels enter the liver at the

hilum or porta hepatis 75-80% of blood supply to the liver

comes from portal vein, which carries oxygen-poor blood from digestive tract, pancreas and spleen

The portal blood carries

Nutrients and toxic materials absorbed in the intestine

Blood cells and breakdown products of blood cells from the spleen

Endocrine secretions of the pancreas and enteroendocrine cells of GIT

The hepatic artery carries oxygenated blood from the liver, providing 20-25% of its blood supply

Blood from 2 sources gets mixed before it perfuses the hepatocytes

The distributing branches of portal vein and hepatic artery supply the sinusoidal capillaries that bathe the hepatocytes

The sinusoids are in intimate contact with the hepatocytes and provide for exchange of substances between blood and liver cells

The sinusoids lead to a central vein, that in turn opens into the sublobular veins

Blood leaves the liver through hepatic veins, which empty into the IVC