Work of the 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 the 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 heart muscle works or contracts about one third of the time 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. 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.

The left ventricle discharges out 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. Answer the questions to the text:

1. How many beats per min does the heart make?

2. What is the total weight of the blood pumped by the heart daily?

3. What is systole?

4. What is diastole?

5. How many phases does each cardiac cycle consist of?

6. What is the role of ventricles?

7. How long does the heart muscle contract?

8. What does the rate of heartbeat depend on?

Exercise 8. Give English equivalents of the following word combinations:

Загальна вага крові; малий круг кровообігу; серцевий м’яз; нервові волокна; загальна маса крові; хвиля скорочення: частота серцебиття; фізичне навантаження; серцевий цикл; дослідницька робота; тривале скорочення шлуночків; велике коло кровообігу; виділяти кров.

Exercise 9. Find in the text 7 words that are formed by conversion:

Model: act → to act

Exercise 10. Make adjectives using the suffix-ant (-ent). Translate them:

Model: difference →different (різний)

Significance, dependence independence, frequency, distance, permanence, assistance, absence, presence, depression.

Exercise 11. Divide the given words into the table. Remember that that there are words which can be used both as a noun and verb:

Contraction, short, determine, blood, systemic, final, rest, follow, physical, compose, pulmonary, contract, research, regulate, weight, depend, cardiac, cycle, chamber, send, possibility, pump, right, act, different, wave, consist, aorta, considerable.

Exercise 12. Match the terms with their definitions:

Exercise 13. Complete the sentences using the information from the text:

1. The atria act as ….

2. Each cardiac cycle consists of … phases.

3. In the adult the heart makes … beats per min.

4. The total weight of the blood pumped by the heart daily is about … tons.

5. The rate of heart contractions is regulated by ….

6. Each beat of the heart is followed by ….

7. The period of rest of the cardiac muscle is called ….

8. The ventricles serve as ….

Exercise 14. Form Participle II of the following verbs. Translate them:

Model: develop (розробляти) →developed (розробленний)

To increase, to pump, to regulate, to compose, to estimate, to discharge, to call, to determine, to receive, to contract

Exercise 15. Open the brackets using the Perfect Tense. Translate the sentences:

1. You ever (be) to Germany?

2. The young scientist (publish) many article since 2000.

3. Today the surgeon (complete) the operation.

4. You (be) to the dissecting room?

5. Recently his respiratory rate (increase) considerably.

6. The patient's sleep (become) sound since he began to take this medicine.

7. The teacher (finish) to examine students this week.

8. After the patient (to take) this medicine, he feels better.

Exercise 16. Translate the sentences using the Perfect Tense:

1. Він тільки що прийшов.

2. Ми ніколи не бачили його.

3. Лікар ще не використовував цей метод лікування. лечения.

4. Він вже прийняв ліки.

5. Я ніколи не зустрічав його тут.

6. Медична сестра вже поміряла температуру хворого.

7. Мій однокурсник тільки що виконав операцію.

8. Ви коли-небудь оглядали хворих.?

Exercise 17. Open the brackets using correct tense form and voice. Translate the sentences:

1. The heartbeat (to produce) the pulsation.

2. On admission to the clinic the physician (to examine) the patient’s heart.

3. The patient’s blood and urine test (to make) the following day.

4. The pain in the heart (to relieve) by a tablet of nitroglycerin.

5. The pain in his heart (to subside) lately.

6. The nurse (to remove) the dressing carefully.

7. The heart sounds (to determine) by the physician by percussion.

8. The nurse already (to give) an injection of the nicotine acid.

Exercise 18. Put questions to the underlined words:

1. The rate of heart contractions are regulated by two groups of nerve fibers.

2. Each beat of the heart is followed by a period of rest for the cardiac muscle.

3. Each cardiac cycle consists of three phases.

4. The period of rest is shorter during greater physical exertion.

5. Physiologists have called the first phase of short contraction of both atria the atrial systole.

6. The rate of the heartbeat depends on different emotions.

7. Scientists have determined that the total weight of the blood is about 10 tons.

8. Research work of many physiologists has given the possibility to estimate the role of the ventricles.

Exercise 19. Arrange in sequence the following sentences. Use them in the story of the cardiac cycle:

1. The total weight of blood pumped by the heart daily is about ten tons.

2. The human heart contracts from the first moment of life until the last one.

3. Each wave of contraction and a period of rest following it compose a cardiac cycle.

4. The heart muscle works or contracts about one third of the time of the person's life.

5. Each beat of the heart is followed by a period of rest for the cardiac muscle.

6. Each cardiac cycle consists of three phases: physiologists have called the first phase of short contraction of both atria — the atrial systole.

7. The period of rest is shorter during greater physical exertion and longer when the body is at rest.

8. The period of rest of the cardiac muscle is called the diastole.

9. The second phase of a more prolonged contraction of both ventricles is called the ventricular systole.

10. The atria act as receiving chambers.

11. The role of the ventricles is to serve as the main pump.

Завдання для самостійної роботи студентів (СРС)

Exercise 1. Learn the new words:

Exercise 2. Read the following paying attention to the rules of reading. Give examples of your own:

th [θ] – th alamus, th erapy, th ermal, th yroid, th umb, ery th rocyte

[ð] – th ey, th is, th at, th en, th em

sh [ʃ] – fle sh, sh elf life, sh oulder, ra sh, sh ape

i + gh [ai] – n igh t, r igh t, h igh, s igh t, l igh t

a + ss, st, sk, ff, ft [a:] – gl ass, m ask, l ast, st aff, aft er, cl ass, c ast

Date: 2015-12-12; view: 3673; Нарушение авторских прав