Text A. The Heart and the Vascular System

The heart is an inner hollow muscular organ placed within the chest and in­cluded in the pericardium. The base of the heart is against the third rib. Its apex is against the interspace between the fifth and sixth costal cartilages. The weight of the heart is about 300 grams (gr) in the male and about 220 gr in the female.

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

The right atrium is larger than the left one, but the walls of the left atrium are thicker than those of the right one/The right ventricle is triangular (треугольный) in form and has' thick walls. The right ventricle is in the anterior part of the heart.jffbe left ventricle is longer and more conical than the right one,? / The walls of the left ventricle are three times as thick as the walls of the right oneyThe valves are located at the entrance and exit (выход) of each ventricle.

The muscular structure of the heart consists of two parts - the muscular layers of the atria and the muscular layers of the 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 circulation. They are called the systemic vessels.

wThe pulmonary circulation 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 contract simultaneously with the action of the heart.

CLASS ASSIGNMENTS

XI. Read the following words and explain the pronunciation of the let­ter combinations in bold type:

Coat, count, cause, law, load, loud, autopsy, saw, soak, sound, nausea, raw, moan, amount, gauze, road

XII. Form and translate the new words by adding:

a) the prefix sub-: divide, tropical, class, cutaneous, costal, family, mucous

b) the prefix inter-: costal, national, muscular, vertebral, ventricular, vas­cular

XIII. Form the Past Participle of the verbs given in brackets. State their functions. Translate the sentences:

The patient (admit) to the hospital was a 45-year-old female. 2. The inner organs (include) in the thoracic cavity are the heart and the lungs. 3. The blood (carry) to the lungs is called venous blood.

XIV. Translate into English:

1. в три раза толще, чем стенки; 2. малый (легочный) круг крово­обращения; 3. большой круг кровообращения; 4. кровообращение в сис­теме воротной вены

XV. Choose the proper Participle. Translate the sentences:

1. The blood vessels (located, locating) on the anterior surface of the arm were dilated. 2. The vessels (carried, carrying) blood to the heart are called veins. 3. The Jungs are the inner organs (included, including) in the thoracic cavity. 4. The muscular structure of the heart (consisted, consisting) of two parts includes muscular layers of the artria and muscular layers of ventricles.

XVI. Read the following sentences and define instead of what words the substitutes 'one - ones', 'that - those' are used:

1. The condition of patient M. is worse than that of patient N. 2. The number of the vertebrae in the coccyx is less than the number of those in the neck. 3. The bones of the lower extremities are longer than those of the upper ones.

XVII. Read Text B. Entitle it. Say what it deals with:

Text В

In the left chamber the atrium and ventricle are separated by the mitral ['maitral] valve.

In the right chamber the atrium and ventricle are separated by the tricuspid [trai'kAspid] valve.

At the point of origin of the aorta in the left ventricle another valve is lo­cated. This valve is called the semilunar [, semi'lu: n3] valve of the aorta.

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