Upper digestive tract

In the upper digestive tract takes place mainly mechanical processing of food associated with its digestion. Nutrient absorption is minimal.

Mentioned processes begin in the mouth where teeth chewing mechanically Melno food. This is especially adapted stools. Comminuting food is mixed with saliva and salivary amylase – cleaving enzyme digestion carbohydrates / sugars, yielding easily spolknutelné wet bite that enters through the pharynx into the esophagus.

The tubular, located in the chest cavity 30-40 cm long body through peristaltic contractions transports swallowed a bite in the stomach. In the esophagus, therefore there is no digestion of food, only the transport authority.

In the stomach leads to further mechanical processing, blending chyme with gastric juices and enzymes. Continued digestion of carbohydrates and, moreover, also occurs to cleave proteins / proteins. This process involved the enzyme pepsin, chymosin and the low pH of 1.5. The pH is so low due to the hydrochloric acid (salt, HCl). Less in the stomach digestion of lipids / fats using lipases. Chyme is peristaltic movements shifted toward pylorickému sphincter from which the food moves into the duodenum / duodenum /. The stomach has a capacity of about 1-2 liters of food and liquid flows directly into the stomach, duodenum.

Do horseshoe bent, duodenal stomach does not result only, but also efferent paths pancreatic and bile. Acidic chyme from the stomach is thanks to them neutralized and digestion. Continues carbohydrates, vigorously digested proteins and fats, and this contributes mainly enzymes trypsin, chymotrypsin, lipase, amylase and bile acids. In addition, the duodenum is the absorption of small amounts of nutrients, e.g. iron and certain drugs.