Liver:-

• It is the largest gland of the human body.
• It is present transversely on the right side of stomach below the diaphragm in the abdominal cavity.
• It is mushroom shaped.
• It is radish brown in colour.
• The lobes of liver are attached by falciform ligament.
• The size is around 15 – 22 cm and weight is around 1.5 – 1.8 kg.The zoological adjectives used for liver is hepato/hepatic.
• The study of liver is called Hepatology.

Morphology of Liver:-

• Liver is divisible into two lobes i.e. larger right lobe and the smaller left lobe.
• The right lobe is further divisible into three lobes. These are

(i) Right central lobe

(ii) Quadrate lobe

(iii)Caudate lobe

• There is a thin walled sac like structure present below the right lobe called bladder.
• The right hepatic duct of right lobe combines with the left hepatic duct to form the common hepatic

duct

• It combines with the cystic duct of gall bladder to form common bile duct.
• The common bile duct combines with the pancreatic duct at ampulla of vater to form hepato

pancreatic duct.• The hepato pancreatic duct opens into the duodenum guarded by sphincter of oddi.Anatomy of Liver.

Histology if Liver :-

• When T.S of Liver (Histologically) is taken, it shows the presence of numerous hepatic lobules.• These are hexagonal and polygonal in nature.
• The hepatic lobules consist of numerous hepatic cells and hepatocytes.
• The hepatic cells are arranged in form of cords called hepatic cord.
• The space within the hepatic cords is called liver sinusoid. These are narrow capillaries, which

store bile.

• There is a central vein/intra lobular vein seen within each hepatic lobule.
• The phagocytic Kupffer’s cells and fat storing adipocytes are present within the liver sinusoid.
• Each hepatic lobule remains encapsulated by fibrous Glisson’s capsule.

Blood supply to Liver

The liver is supplied with oxygenated blood by hepatic portal vein and hepatic artery. The deoxygenated blood is collected by hepatic vein.

Path of Bile Flow:-

• There are small bile capillaries within the hepatic cords called bile canaliculi.
• These bile capillaries open to inter lobular bile duct through Herring’s canal.

Function of Bile:-

• Bile makes the medium alkaline in duodenum.
• It stops the actions of gastric juice and HCL.
• Bile is anti-septic in nature.
• It carries out emulsification of fat. (Breaking down of complex fats into smaller fat droplets)
• It stimulates peristaltic movement.
• It activates pancreatic lipase.
• The fat soluble vitamin like vitamin A, D, E, K are stored in bile

Composition of Bile:-• Bile is a non enzymatic alkaline juice.

pH = 7.5 – 8.5

Water – 89%

Others – 11%(i) Inorganic Substances (0.8%): Chlorides, Phosphates, Sulphates, Bicarbonates of Na+

, K+,Ca++,Mg++, Zn++ etc.

(ii) Organic Substances (10.2%)

(a) Bile Salt: Sodium glycocholate, Sodium taurocholate

(b) Bile Pigment: Bilirubin (yellow), Biliverdin (green)

(c) Others: Mucin, Cholesterol, Fatty acidsFunction of Liver:-

• The liver secretes bile
• Excretion: The bile pigments produced due to worn out RBC are excreted in faecal materials.
• Glycogenesis: It is the process of conversion of excess glucose to glycogen (Insulin).
• Glycogenolysis: It is the process of conversion of glycogen to glucose. (Glucagon)
• Gluconeogenesis: It is the formation of glucose from non carbohydrate source.
• Lipogenesis: It is the process of conversion of lipid or fat from excess glucose.
• The formation of Amonia, Urea, Uric acid occurs in liver.
• The anti coagulant heparin is produced and stored in liver.
• The procoagulant prothrombin and fibrinogen are produced and stored in liver.
• The fat soluble vitamins like Vitamin A, D, E, K are stored in liver (Vitamin A is synthesized in

liver).

• Haemopoiesis: It helps in formation of blood.

PRESENTED BY:- Sarmistha Swain (Lecturer in Zoolozy)