1.

Question : Describe the process of digestion of food in man .

Answer»

Solution :Process of digestion starts in mouth where secretion of three pairs of salivary glands known as saliva mixed with food Saliva contains an enzyme ptyalin (Amylase) which digests starch and converts in into maltose.
From mouth food reaches the stomachwhere gastric glands are present having threetypes of cells. Thesesecrete hydrochloric acid, protein digesting enzyme (Pepsin) and mucusrespectively. Small amountof gastric lipase is also present in the gastric juice secreted by theseglands. Pepsin digests proteinand converts it intopeptones. Hydrochloric acid kill bacteria presentin the food, prevents fermentation of semi-digested food and provides acidic medium which is essential for digestionof protein in stomachby the enzyme pepsin as it can act only in acidic medium. Gastric lipase partially breaks downlipids (fat) into glycerol and FATTY acids.
From stomach semi-digested food reaches the firstpart of small intestinecalled duodenum. Itis a U shaped structureand receives the secretion of common duct. It bringssecretions of liver (Bile) and pancreas (Pancreatic juice) to small intestine.
Bile emulsifies fat and converts fat MOLECULES into small globules and chages and medium of food from acidicto alkaline.
Pancreatic juice contains following enzymes :
(i) Trypsin which converts proteinsinto peptone and peptides.
(ii) Amylase which convertsstarch into SIMPLE sugar.
(iii)Lipase which converts fats into fatty acid and glycerol.
walls of small intestinealsohave glands whose secretion in known as succus entericus. This intestinal juice completes the digestion of fat, proteinand CARBOHYDRATE. In small intestine the final end product of protein is amino acid, of starch is glucose and fat is finally CONVERTEDINTO fatty acidand glycerol.
Finally , the digestedfood is absorbed by the walls of small intestine which containsabundantfinger-like projections called villi whichhave rich supply of blood.


Discussion

No Comment Found

Related InterviewSolutions