Digestion encompasses the different steps of the transformation of food into nutrients that are absorbable by the organism. The process begins in the mouth where, during chewing, proteins called enzymes are secreted by the salivary glands and start to break down large molecules into smaller substances. The ball of food, staying together through the buccal passage, passes into the esophagus, then the stomach, where enzymes contained in the gastric juice, combined with other reactions, take up the work of reducing the food's size into absorbable molecules. The passage of these molecules through the gastric mucus membrane, inner wall of the stomach, and into the blood, permits the distribution of the substrates to the entire organism, which are sources of energy that are indispensable to the functioning of various organs. The unused residue is then expelled in stools and urine.
Original article published by
. Translated by Jeff