Following are the different types of glandular secretions in our gut which help in digestion of food.
Secretions from Gastric Glands: The gastric glands secrete gastric juice which contains hydrochloric acid and the enzyme pepsin. In infants, rennin is also secreted by the stomach. Rennin helps in digestion of milk.
Secretions from Liver: Liver makes the bile juice. Bile does not contain any enzyme but plays an important role in digestion. Bile facilitates emulsification of fats so that digestion of fat can be easier. Bile also provides alkaline medium so that the enzymes in the small intestine can work properly.
Secretions from Pancreas: Pancreas secretes pancreatic juice which contains inactive enzymes; like amylase, lipase, nuclease; trypsinogen and chymotrypsinogen. Trypsinogen is activated by an enzyme enterokinase, secreted by intestinal mucosa into active trypsin. Trypsin then activate other enzymes in the pancreatic juice. While amylase digests carbohydrate; trypsin/chymotrypsin digests protein.
Secretions from Small Intestine: Small intestine secretes succus entericus which contains various enzymes; like dipeptidase, lipase, lactase, etc.
End Products of Digestion: The end products of digestion are simple substances like glucose. amino acids, fatty acids and glycerol. These substances can be easily absorbed by the villi present in small intestine.