ЛЕКЦИЯ № 38. The digestive tract structure

The gastrointestinal tract and associated organs are collectively called the digestive system. This system is responsible for receiving food and breaking it down by using enzymes from the glands and by the movement of the various parts of the intestinal tract; for absorption of these components into the blood; and for eliminating undigested food and certain metabolic wastes from the body. The alimentary canal extends from the mouth to the anus. It is a long tube varying in size and shape depending on what function the particular part performs. The tract has a very good blood sup ply, because food, once it is broken down, has to be absorbed into the bloodstream. The mouth contains the tongue and the teeth and communicates with the salivary glands situated round it. Behind the nose and mouth is the pharynx. Leading from the pharynx is a mus cular tube called the esophagus which passes down the thoracic cavity to the stomach. The stomach lies below the diaphragm in the upper left side, of the abdominal cavity. The opening into the small intestine is called the pylorus and is closed by the pyloric sphincter. The small intestine is a muscular tube coiled up in the abdominal ca vity. It is divided into three parts; the duodenum, the jejunum, and the ilium. The large intestine, also a muscular tube but with wider lumen than the small intestine, is often called the colon. It is divided into several different parts: the, cecum, the ascending colon, the transverse colon, the descending colon, the rectum and the anal canal. The glands belonging to the digestive system are the salivary glands, the liver and the pancreas.

Stomach is probably the most distensible of any in the human body. The proximal portion is the cardiac portion; the portion above the entrance of the esophagus is the fundus; the distal portion is the pylo-ric part; and the body is between the fundus and the pyloric part.

The coats of the stomach are four: an outer, peritoneal or serous coat; a muscular coat, made up of longitudinal, oblique, and circular fibres; a submucous coat; and tine mucous coat or membrane forming the inner lining.

Gastric glands, which are in mucous coat, secrete gastric juice containing hydrochloric acid and other digestive enzymes into the cavity of the stomach. The glands of the fundus and body moot important in the secretion of gastric juice.

The shape of the stomach varies from individual to individual and from time to time in the same individual depending upon the degree of digestion, degree of contraction, and the age and the body-built of the individual. Frequently in more J-shaped than U-shaped so that its greater curvature can even lie in the greater pelvis. Cardia and fundus are relatively fixed and, hence, tend to move only with the respiratory excursions of the diaphragm.

New words

gastrointestinal tract – желудочно-кишечный тракт

associated – связанный

collectively – все вместе

digestive system – пищеварительная система

responsible – ответственный

receiving – получение

food – пища (еда)

breaking – ломка (нарушение)

using – использование

enzymes – ферменты

intestinal tract – кишечный тракт

absorption – поглощение

eliminating – устранение

undigested – неусвоенный

metabolic wastes – метаболические

alimentary – отходы

extends – пищевой

anus – задний проход

tube – труба

tract – трактат

round – вокруг

esophagus – пищевод

diaphragm – диафрагма

abdominal – брюшной

pylorus – пилорус pyloric

sphincter – пилорический сфинктер

coiled up – свернутый

Future simple tense (действие совершится в будущем)

Спряжение глагола to work в Future simple tense Таблица 9

Раскройте скобки, употребляя глаголы в Present Continuous, Present Simple или в Future Simple.

1. When you (to get) up every day? – I (to get) up at seven o'clock.

2. My brother usually (not to get) up at seven o'clock. As a rule, he

(to get) up at six o'clock, but tomorrow he (to get) up at seven o'clock.

3. Why she (to come) home so late to morrow?

4. We (to go) to the country the day after tomorrow.

5. Our friends always (to go) to the country for the week-end.

6. Look! The kitten (to play) with its tail.

7. Your parents (to watch) TV now?

8. My sister (not to rest) now. She (to help) mother in the kitchen. She (to help) mother in the kitchen every day.

9. Where she (to go) tomorrow?

10. She (to go) to the country with us tomorrow?

11. They (to stay) at home tomorrow.

12. What you (to do) now? I (to see) that you (not to read).

13. When you (to finish) your homework? It (to be) very late, it (to be) time to go to bed.

14. How you usually (to spend) evenings?

15. What you (to do) in the country next summer?

16. They (not to drink) ten now. I (to think) they (to watch) TV.

17. What your father (to drink) in the evening?

Answer the questions.

1. How are the gastrointestinal tract and associated organs collectively called?

2. What is the digestive system responsible for?

3. Where does the alimentary canal extend?

4. What shape do the alimentary canal have?

5. Has the tract a very good blood sup ply?

6. Why the tract has a very good blood sup ply?

7. What is behind the nose and the mouth?

8. What leads from the pharynx?

9. Under what does the stomach lie?

10. How does the shape of the stomach vary?

Make the sentences of your own using the new words (10 sentences). Find the verb to be in the text. Explain why it is used in such a way?