Interspace [,ints'speis] проміжок; інтервал

mitral fmaitrsl] мітральний

tricuspid [trai'kAspid] тристулковий

semilunar [,semi'lu:na] (на)півмісяцевий; серповидний

triangular [,trai'aengju:ta] трикутний; тригранний

within - в, у межах; всередині

separate ['seprat] окремий, відокремлений; відокремлювати(сь) thick - товстий; щільний; густий coat [кзої] оболонка; наліт; шар dilate [dai'leit] розширювати(сь) contract [kant'ra;kt ] скорочуватись

Exercise 3. Read and translate the following word combinations.

Chamber ['tfeimba]: the heart consist of two separate chambers: the right atrium and th. right ventricle are in the right chamber;

thick [бік]: a thick wall; the walls of the left atrium are thick; the left ventricle has thic-walls;

pulmonary: pulmonary artery, pulmonary circulation; pulmonary diseases; pulmonar function; pulmonary valve;

dilate: dilated; to be dilated, the vessels dilate; the heart dilates and contracts.

Exercise 4. Read the text and retell it.

Heart and Vascular System

The heart is an inner hollow muscular organ placed within the chest and included in x:.-pericardium. The base of the heart is against the third rib. Its apex is against the interspa.: between the fifth and sixth costal cartilages. The weight of the heart is about 300 g in the m_._; and about 220 g in the female.

The heart consists of two separate chambers divided by the septum. Each of the chambe-has two connected parts: the atrium and the ventricle. The atrioventricular valves separate atria from the ventricles.

In the left chamber the atrium and ventricle are separated by the mitral valve. In the rig: chamber the atrium and ventricle are separated by the tricuspid valve.

At the point of origin of the aorta in the left ventricle another valve is located. This va/ -. is called the semilunar valve of the aorta.

At the point of origin of the pulmonary artery in the right ventricle the fourth valve located. It is called the semilunar valve of the pulmonary artery.

The right atrium is larger than the left one, but the walls of the left atrium are thicker t'r._-those of the right one. The right ventricle is triangular in form and has thick walls. The ri;^_ ventricle is in the anterior part of the heart. The left ventricle is longer and more conical t'r „-the right one. The walls of the left ventricle are three times as thick as the walls of the right or.-. The valves are located at the entrance and exit of each ventricle.

The muscular structure of the heart consists of fibrous bands divided into two groups: -. first ones are the fibrous bands of the atria and the second ones are the fibrous bands of: : ventricles.

The vascular system consists of three groups of vessels: arteries, veins and capillaries. The vessels carrying blood to and from the tissues of the body compose the general syste^-They are called the systemic vessels.

The pulmonary system is formed by the vessels carrying blood to and from the lungs The portal system is formed by the veins passing to the liver.

Most of the arteries are composed of three coats. The arteries dilate and com: simultaneously with the action of the heart.

Exercise 5. Describe the structure of the heart.

Exercise 6. Read and translate the text, make up questions based on it.

Work of Human Heart

The human heart contracts from the first moment of life until the last one. The contractions of the heart pump the blood through the arteries to all the parts of the body. Scientists have determined that the total weight of blood pumped by the heart daily is about ten tons.

The rate of heart contractions is regulated by two groups of nerve fibers: it varies in different persons and at different age.

Physiologists have determined that in the adult the heart makes from 60 to 72 beats per minute. In children the rate of heartbeat is much higher. Research work of many scientists has helped to determine that the rate of heartbeat increases depending on different emotions.

Each beat of the heart is followed by a period of rest for the cardiac muscle. Each wave of contraction and a period of rest following it compose a cardiac cycle.

Research work has given physiologists the possibility to find out that the muscle works or contracts about one third of the person's life. The period of rest is shorter during greater physical exertion and longer when the body is at rest.

Each cardiac cycle consists of three phases: physiologists have called the first phase of short contraction of both atria the atrial systole [" sistsli]. They have called the second phase of a more prolonged contraction of both ventricles the ventricular systole. The period of rest of the cardiac muscle is called the diastole [dai'cestali].

The left ventricle discharges the blood received by the left atrium from the pulmonary circulation through the aorta to the systemic circulation.

The blood received from the systemic circulation by the right atrium is discharged out of the right ventricle to the lungs through the pulmonary arteries.

Prolonged research work of many physiologists has given the possibility to estimate the role of the ventricles which serve as the main pump. The atria act as receiving chambers. The contraction of the atria which sends the final portion of the blood into the ventricle is considerably less.

Exercise 7. Read the text and speak about heart diseases and their treatment.

Heart Diseases

There are many ways of classifying heart diseases. The anatomy of the heart forms one group of heart pathology: