Text 1. Digestive system

The digestive system, or gastrointestinal tract, begins with the mouth, where food enters the body, and ends with the anus, where solid waste material leaves the body. The primary functions of the organs of the digestive system are threefold.

First, complex food material which is taken into the mouth (ingestion) must be digested, or broken down, mechanically and chemically, as it travels through the gastrointestinal tract. Complex proteins are digested to simpler amino acids; complicated sugars are reduced to simple sugars, such as glucose; and large fat molecules are broken down to fatty acids and triglycerides.

Second, the digested food must be absorbed by passage through the walls of the small intestine into the bloodstream so that the valuable energy-carrying nutrients (sugars, amino acids, fatty acids) can travel to all the cells of the body. Within the cells, sugars and fatty acids can be burned in the presence of oxygen (catabolism), thereby releasing the energy stored in the food matter. Amino acids are used by the cells to build large protein molecules (anabolism) necessary for growth and development.

The third function of the gastrointestinal tract is to eliminate the solid waste materials which are unable to be absorbed by the small intestine. The solid wastes (feces) are concentrated in the large intestine and finally passed out of the body through the anus.

Exercise 1. Match the following terms in a) with their meanings in b):

a) 1. deglutition; 2. absorption; 3. mastication; 4. digestion; 5. peristalsis;
6. excretion; 7. anastomosis; 8. regurgitation.

b) 1. bringing food back up the gastrointestinal tract; 2. breakdown of complex substances; 3. new opening up between two hollow organs or fibers;
4. contraction and relaxation of muscles to propel food along the gastrointestinal tract; 5. formation of wastes and removal from the body; 6. passage of simple nutrients into the bloodstream; 7. swallowing; 8. chewing.

Exercise 2. Translate into English:

Шлунково-кишковий тракт; клітини; жирні кислоти; ковтання; амінокислоти; кисень; усувати; тонка кишка; товста кишка; живильні речовини.