Question

How is the small intestine adapted for digestion?

Answer 1

Hint: The semi digested food from the stomach mixed with gastric secretion is passed into the duodenum through the pyloric printer from time to time. In the small intestine, the chyme receives three alkaline secretions bile pancreatic juice and intestinal juice which helps in the digestion of food.

Complete answer:
-Small intestine supports in the complete digestion of food by making use of some secretions that occur from various glands/regions in the body. All the secretions are found to be alkaline in nature.
-Bile is secreted by the liver and it has no enzymes. Thus it has no chemical action on food. Through the process called emulsification, its salts, namely sodium glycocholate and sodium taurocholate, reduce the surface tension of large fat droplets and divide them into small ones. Bile salt also forms a thin coating around tiny fat droplets to keep them from coalescing. The tiny fat droplets present lipases with greater surface area.
-Pancreatic juice contains pancreatic lipase, which is the main enzyme that digests fat. It hydrolyses parts in stages. Pancreatic juice contains carbohydrates named pancreatic amylase that hydrolyses more starch and glycogen to dextrans and the latter two double sugar maltose and isomaltose.
-Intestinal juice is secreted by intestinal glands and it contains lipases. This enzyme is present in the intestinal epithelial cells and it is released in small amounts in the intestinal juice. The life is found in the intestinal juice hydrolyses some triglycerides and diglycerides to monoglycerides and fatty acids. Intestinal juice contains its carbohydrases intestinal amylase, maltase, isomaltase, dextrinase, sucrase and lactase which convert the entire carbohydrate part of the ingested food into glucose, fructose and galactose.
-Fatty acids, glycerol and monoglycerides are obtained as the end products of fat digestion.
The digestion of the nucleic acids also occur in the small intestine. In the pancreatic and intestinal juices, the enzymes which hydrolyze them are present. Nucleases, nucleotidases and nucleosidases are included here.

Note: The digested food passes from the alimentary canal into the blood and lymph through its mucous membrane for the process of absorption. The absorption of food mainly occurs in the small intestine.