Liver(Largest gland of the body) :
- Second largest organ of the body (largest organ of the body is skin).
- Heaviest organ of the body.
- Location : Present below the diaphragm in the abdominal cavity on the right side.
- Falciform ligament suspend the liver from diaphragm and divide into right and left hepatic lobe
- Right hepatic lobe is internally divided into quadrate lobe and caudate lobe.
- Liver is covered by a collagenous connective tissue called fibrous coat.
- Fibrous coat provide shape and protection to the liver.
Duct system :
- Right hepatic duct + Left hepatic duct = Hepatic duct / bile duct
- Hepatic duct + Cystic duct = Common bile duct / duct of choleodochus
- Common bile duct + duct of wirsung (from pancreas) = hepatopancreatic duct / ampulla of vanter
- Ampulla of vanter open into duodenum and pours pancreatic juice and bile juice.
- Sphincter of oddi = guards opening of hepatopancreatic duct into small intestine
- Sphincter of Boyden guards opening of common bile duct into hepatopancreatic duct and it facilitate feeling of gallbladder.
- Hepatic lobules are the structural & functional unit of liver.
- Each Hepatic lobule is covered by a thin connective tissue called a Glisson's capsule.
Bile juice :
- Normal volume = 800-1000 ml per day
- pH of bile juice = 4.6 -8.6
- composition :
(i) Water
(ii) Bile salt(Na/K salts of cholic acid)
(a) Sodium glycocholate (sodium + glycine + cholic acid)
(b) Sodium taurocholate (sodium + Laurine + cholic acid)
(c) NaHCO3
(iii) Bile pigments :
Billirubin / Biliverdin (breakdown of heme of hemoglobin).
Breakdown product of bilirubin ::
Stercobilin = yellow colour to faeces
Urochrome (Urobilin and Urobilinogen) = yellow colour to urine
(iv) Cholesterol
(v) Phospholipid
Function of bile juice :
(i) Helps in emulsification.
(ii) Provide ideal pH for activation of pancreatic enzyme.
(iii) Kill microbes.
(iv) Neutralize the acidic chyme.
(v) Helps in detoxification mechanism.
(vi) Perform urea cycle.
(vii) Stores glycogen ,fat soluble vitamin and vitamin b12 (water soluble).
(viii) Help in activation of vitamin D(natural vitamin).
(ix) Produce an anticoagulant (heparin) which prevents blood clotting inside the vessels.
(x) Liver also produce to proteins -- prothrombin and fibrinogen which help in clot formation at injury to check bleeding.
(xi) Acts as an erythropoietic organ(forms RBC) in embryo.
(xii) Liver also acts as haemolytic organ (breaks old RBCs).
(xiii) Kupffer cells of liver sinusoids act as phagocytes which eat up the dead cells and bacteria.
Note :- Bile juice does not contain any enzyme and it is partially a digestive juice and partially an excretory product.