Question

In which part of the digestive system is water absorbed?

Answer 1

Hint: The absorption of water is passive and takes place along with other solutes only and is absorbed in the longest part of the digestive system.

Complete answer:
Among all the food that we ingest, 80 percent of the electrolytes present in them, and 90 percent of water are absorbed in the small intestine. Although the entire small intestine is involved in the absorption of water and lipids, water reabsorption is the main function of the large intestine. It can absorb up to 300 ml of water in a day. By the time the food enters the large intestine, approximately 80% of this fluid has already been absorbed by the small intestine. The large intestine is much broader than the small intestine and takes a much straighter path than the small intestine. The main purpose of the large intestine is to absorb water and salts from the material that has not been absorbed by the small intestine. It also helps to get rid of any waste products left after reabsorption. The absorbed fluid from the epithelium then goes into the lymphatic system via the lacteals.

Note: -Sodium ions present in the water are absorbed by either diffusion or active transport using ATP against a chemical gradient. It also facilitates the movement of other molecules like chlorine ions, glucose, amino acids, etc. to move along with it into the cell.
-Vitamins are not digested but are only absorbed in the gastrointestinal tract.
-Fat-soluble vitamins are absorbed along with the dietary fat while water-soluble vitamins are absorbed by passive diffusion.