Text A. The alimentary tract

The alimentary tract is a musculomembraneous canal about 8.5 metres in length. It extends from the oral cavity to the anus. It consists of the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. The liver with the gallbladder and the pancreas are the large glands of the alimentary tract.

The first division of the alimentary tract is formed by the mouth. Important structures of the mouth are the teeth and the tongue which is the organ of taste. The soft and hard palates and the salivary glands are also in the oral cavity.

From the mouth food passes through the pharynx to the esophagus and then to the stomach. The stomach is a dilated portion of the alimentary canal. It is in the upper part of the abdomen under the diaphragm. The stomach serves as a container of food which is partly digested in it. The capacity of the stomach is from 2.14 to 4.28 litres.

The intestines occupy chiefly the central portions of the abdominal cavity which is the largest cavity in the body separated from the thoracic one by the diaphragm. From the stomach the food passes in small portions into the small intestine where it undergoes further mechanical and chemical changes. The small intestine is a thin-walled muscular tube about 6.5 metres long. It is composed of the duodenum, jejunum and ileum.

As the contents of the small intestine cannot move back they may freely pass into the large intestine which is about 1.5 metres long. The large intestine is divided into caecum, colon and rectum.

The liver is the largest gland in the human body that weights about 1.5 kg. It is in the right upper part of the abdominal cavity under the diaphragm. Everybody must know that the liver plays a very important role in the vital activities of the organism. It secretes bile which participates in the digestive process and has a defensive function, i.e. some toxic substances are detoxified in the liver.

The gallbladder is a hollow sac lying beneath the right lobe of the liver. It serves as a bile reservoir.

The pancreas is a long thin gland lying under and behind the stomach. It secretes digestive juice containing enzymes and other substances which take part in the chemical processes of digestion.

TASKS

I. Find the words in B having the close meaning with the words in A:

A. chest, to take part, to place, big, digestive, to perform, mouth, shape, main, body,

toxic, portion, disease, drug, doctor

B. to locate, part, large, thorax, ailment, oral cavity, to participate, physician, form,

organism, alimentary, medicine, chief, to carry out, poisonous

II. Complete the sentences:

1. The alimentary tract begins with the ….

2. The … is the organ of taste.

3. The teeth and the salivary glands are in the ….

4. From the mouth food passes through the pharynx into the ….

5. The … serves as a container of food.

6. The … is the largest cavity in the human body.

7. From the stomach food passes into the ….

8. The … is divided into caecum, colon and rectum.

9. The … is the largest gland in the human body.

10. The liver secretes ….

11. The … serves as a bile reservoir.

12. The … secretes digestive juice containing enzymes.

III. Describe the location of the organs:

the tongue, the stomach, soft and hard palates, the small intestine, the large intestine, the liver, the gallbladder, the pancreas

IV. Match the adjective from A to the noun from B:

A B

alimentary tongue

large function

salivary glands

central portion

abdominal cavity

chemical body

human activities

vital tract

digestive juice

toxic substances

defensive palate

coated intestine

soft changes

V. Open the brackets:

1. The first division of the alimentary tract is (forming, formed) by the mouth.

2. The stomach is a (dilating, dilated) portion of the alimentary tract.

3. The intestines occupy the central portion of the abdominal cavity (separating,

separated) from the thoracic one by the diaphragm.

4. The liver secretes bile (participating, participated) in the digestive process.

5. The pancreas is a gland (lying, lain) under and behind the stomach.

VI. Answer the questions:

1. What organs does the alimentary tract consist of?

2. What are the main structures of the oral cavity?

3. What is the tongue?

4. Where does food pass from the mouth?

5. What is the role of the stomach?

6. What is the largest cavity in the human body?

7. What are the chief portions of the small intestine?

8. What is the large intestine divided into?

9. What role does the liver play?

10. What does the liver secrete?

11. What process does bile participate in?

12. What does the gallbladder serve as?

13. What does the pancreas secrete?

VII. Say everything you know about the digestive system:

VIII. Translate the text using a dictionary: