Exercise 5. A) Make up collocations using words from both columns

pulmonary	blood
blood	fluid
tissue	circulation
high	mobility
respiratory	pressure
deoxygenated	system

b)Fill in the gaps with the collocations from above.

1. Closed systems have a relatively high … .
2. Since there is no distinction between blood and … in such a system, the fluid is called hemolymph.
3. The … is the circulation of … from the heart to the lungs, oxygenated blood returns to the heart from the lungs.
4. Vertebrates have closed circulatory systems in close association with the … .
5. High blood pressure enables nutrients and oxygen to be delivered quickly to tissues and supports the high metabolic rate associated with the relatively … of some animals.

Exercise 6. Translate from Russian unto English.
1. У млекопитающих кровеносная система состоит из крови, системы кровеносных сосудов и сердца. 2. Кровеносные системы могут быть классифицированы как закрытые и открытые. 3. Открытую кровеносную систему можно обнаружить у моллюсков и членистоногих. 4. Закрытые кровеносные системы имеют довольно высокое кровяное давление. 5. У млекопитающих два круга кровообращения – легочный и системный.

Exercise 7. Answer the questions to the text.

1. What is circulatory system responsible for?

2. What are the main parts of the circulatory system?

3. How can circulatory systems be classified?

4. How does an open circulatory system work? Give examples of animals with an open circulatory system.

5. What are the main characteristics of a closed circulatory system?

6. What is the difference between the single circulatory and double circulatory systems?

7. Describe two circuits of the double circulatory system. Give examples of animals having double circulatory system.

TEXT B

THE MAMMALIAN HEART

VOCABULARY LIST TO TEXT B

aortic (valve) adj	[eɪˈɔː.tik ]	аортальный (клапан)
atrium (atria) n	[ˈeɪ.tri.əm ]	предсердие
backflow n	[ˈbæckfloʊ]	обратный ток жидкости
chamber n	[ˈtʃeɪmbə(r) ]	камера
contract v	[ˈkɒntrækt ]	сокращаться
enclose n	[ɪnˈkləʊz ]	заключать
endocardium n	[ɪnˈdɒkɑːdɪəm ]	эндокард
epicardium n	[ haɪdrəʊˈstætɪk ]	эпикард
inferior vena cava n	[ɪnˈfɪəriər ]	нижняя полая вена
mitral (valve) adj	[ˈmaitrəl]	митральный (клапан)
myocardium n	[ˌmaɪəˈkɑːdiəm ]	миокард
oxygenate v	[ˈɒk.sɪ.dʒə.neɪt ]	обогащать кислородом
pericardium n	[ˌperɪˈkɑːdiəm ]	перикард
protective (sac) n	[prəˈtek.tɪv ] [ sæk ]	защитный мешок
pulmonary (valve) adj	[ˈpʌl.mə.nə.ri ]	легочный (клапан)
superior vena cava n	[suːˈpɪəriə(r) ]	верхняя полая вена
tricuspid (valve) adj	[traɪ-ˈkʌspɪd]	трехстворчатый клапан
valve n	[vælv ]	клапан
ventricle n	[ˈven.trɪ.kl̩ ]	желудочек

The heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients. It also assists in the removal of wastes. The heart is located between the lungs in the middle of the chest.

In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria; and lower left and right ventricles. Commonly the right atrium and ventricle are referred to as the right heart and left atrium and ventricle as the left heart. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The walls of the heart are made up of three layers: epicardium, myocardium, and endocardium.
The heart pumps blood through both circulatory systems. The right and left sides of the heart work together. The pattern described below is repeated over, causing blood to flow continuously to the heart, lungs, and body.
Right Side of the Heart
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart.
As the atrium contracts, blood flows from the right atrium into the right ventricle through the open tricuspid valve.
When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.
As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

Left Side of the Heart
The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium of the heart.
As the atrium contracts, blood flows from the left atrium into the left ventricle through the open mitral valve.
When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts.
As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta and to the body.

Exercise 8. Looking at the picture above, describe the flow of blood in the mammalian heart.

Exercise 9. Fill in the gaps with the appropriate words given below.
1. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right …; and lower left and right … .
2. The heart is enclosed in a … sac, the pericardium.
3. Blood enters the heart through two large veins, emptying oxygen-poor blood from the body into the … atrium of the heart.
4. The pulmonary … empties oxygen-rich blood from the lungs into the left atrium of the heart.
5. As the ventricle contracts, blood leaves the heart through the aortic …, into the aorta and to the body.
(valve, right, protective, atria, ventricles, vein)