Digestion is the process that involves The breakdown of food into small components. Further, they get absorbed and assimilated into the body. Digestion includes three stages. The first stage is when the gastric juices are secreted in response to the smell and sight of food is the cephalic phase. The second stage includes the gastric phase of digestion and the third stage is the intestinal phase of digestion. Complete answer: Digestion is the form of catabolism which is based on how food is broken down: mechanically and chemically. In mechanical digestion, the physical breakdown of large pieces of food into smaller pieces which is accessed by digestive enzymes. The enzymes break the complex food into smaller molecules during the process of chemical digestion. The food enters the human body and mechanical digestion takes place which is followed by the action of mastication and wetting the contact of saliva. The Saliva lubricates the food and the starch digestion takes place. The food gets in the form of a small round slurry mass which is known as a bolus. This bolus travels down through the esophagus and into the stomach by peristalsis. Hydrochloric acid and pepsin get secreted which may damage the stomach wall. The stomach secreted mucus. Protein digestion takes place to buy Paris dialysis which allows the mass of food to mix with the digestive enzymes which results in a thick liquid called chyme. Chime is fully digested and is absorbed into the blood and absorption takes place in the small intestine. The water and minerals get reabsorbed into the blood in the small intestine. The elimination of waste materials takes place from the rectum through defecation. Additional information: Protein is digested in the stomach and duodenum by three main enzymes: pepsin, trypsin, and chymotrypsin. Pepsin is secreted by the stomach. Trypsin and chymotrypsinogen are secreted by the pancreas which break down the proteins into polypeptides. They are broken down by various exopeptidases and endopeptidases into amino acids. The digestion of fats takes place in the small intestine which produces the hormone that releases pancreatic lipase from the pancreas and bile juice from the liver. These help in the emulsification of fat for the absorption of fatty acids. The complete digestion of fat molecules results in the mixture of mono and diglycerides, fatty acids, and some digested glycerol molecules. Digestion is a process that is controlled by several factors which include pH. The pH of The Saliva present in the mouth is 6.8. The pH of the small intestine is about 8.5. Note: An average person can produce two pints of saliva every day. The muscles present in the esophagus act like a giant wave. The small intestine has three parts: ileum, jejunum, and duodenum. the layer of mucus produced by the stomach every two weeks which protects itself. The stomach is not involved in much digestion and food doesn't need gravity to get to our stomach.