Step Three of the Digestive System
In the third stage of the digestive system, the food travels to the stomach. Stomach is a fascinating organ with many functional forms (Kopf-Maier, 2004). There are three areas of stomach: the upper part is fundus, the middle part is called the body, and the lower part is the pylorus. Long muscles run along the length of the stomach and circular muscles go around it. The muscles contract and relax about three times every minute, churning up food and making sure it is mixed with the gastric juices (Parramon, 1994). The stomach is made up of the same layers as esophagus. The mucosa contains the gastric glands that produce the liquid called the gastric juice. The lining of the stomach is protected by a layer of mucus that prevents the gastric juices from damaging the stomach itself (Ballard, 1997).
The muscles in stomach do the mechanical party of the digestion and the gastric juices do the chemical part of the process. The prime function of the gastric juices, which are composed of water, hydrochloric acid, and enzymes, is the transformation of the proteins in food into amino acids, through the action of an enzyme called pepsin. The hydrochloric acid is also responsible for achieving the pH2 within the stomach. The pH in the stomach kills bacteria present in ingested food (Johnstone et al, 2014). The carbohydrates are not altered in the stomach, they get their transformation from saliva in the mouth. The fats begin to be metabolized through the enzyme lipase. This process does not go very far because the lipase is found in very small quantities in the stomach and the fats are broken down in the intestine (Parramon, 1994).
In the third stage of the digestive system, the food travels to the stomach. Stomach is a fascinating organ with many functional forms (Kopf-Maier, 2004). There are three areas of stomach: the upper part is fundus, the middle part is called the body, and the lower part is the pylorus. Long muscles run along the length of the stomach and circular muscles go around it. The muscles contract and relax about three times every minute, churning up food and making sure it is mixed with the gastric juices (Parramon, 1994). The stomach is made up of the same layers as esophagus. The mucosa contains the gastric glands that produce the liquid called the gastric juice. The lining of the stomach is protected by a layer of mucus that prevents the gastric juices from damaging the stomach itself (Ballard, 1997).
The muscles in stomach do the mechanical party of the digestion and the gastric juices do the chemical part of the process. The prime function of the gastric juices, which are composed of water, hydrochloric acid, and enzymes, is the transformation of the proteins in food into amino acids, through the action of an enzyme called pepsin. The hydrochloric acid is also responsible for achieving the pH2 within the stomach. The pH in the stomach kills bacteria present in ingested food (Johnstone et al, 2014). The carbohydrates are not altered in the stomach, they get their transformation from saliva in the mouth. The fats begin to be metabolized through the enzyme lipase. This process does not go very far because the lipase is found in very small quantities in the stomach and the fats are broken down in the intestine (Parramon, 1994).