Question

Discuss the role of the hepatopancreatic complex in the digestion of carbohydrate, protein and fat components of food.

Answer 1

Hepatopancreatic complex :

The hepatopancreatic complex is made up of the liver, pancreas and its associated ducts. The ducts are as follows:-
● Common bile duct is formed by joining the cystic duct from the gallbladder and common hepatic duct.
● Common bile duct joins with the main pancreatic duct to form hepatopancreatic ampulla which opens into the duodenum. The opening of which is guarded by a sphincter of Oddi.


Role of liver :

The liver secretes bile juice. Bile helps in emulsification of fats. It also provides an alkaline medium which is useful for the functioning of enzymes present in the small intestine.

Role of gall bladder :

The bile is stored and concentrated in the gall bladder. The presence of food contracts the gall bladder to release the bile, through the common bile duct, to the duodenum.

Role of pancreas :

The pancreatic juice contains inactive enzymes trypsinogen, chymotrypsinogen, procarboxypeptidase, amylases, lipases and nucleases. Trypsinogen is activated by an enzyme, enterokinase into trypsin which further activates various enzymes in the following way:-


Digestion of carbohydrate :

Polysaccharides are converted to disaccharides by pancreatic amylase.


Digestion of fats:

The pancreatic lipase acts upon emulsified fat (triglycerides) and breaks them down into diglycerides and subsequently into monoglycerides.


Digestion of proteins :

Proteins present in the chyme reaching the intestine are acted upon by the proteolytic enzymes (trypsin, chymotrypsin, carboxypeptidase) of pancreatic juice and hydrolysed as follows:-