Note that the pressure-volume relationship is different with deflation than with inflation of air (hysteresis). The compliance of the lungs is greater (the lungs are more distensible) in the middle volume and pressure ranges.

At high volumes and expanding pressures, the compliance is lower (the lungs are stiffer). Even when the lung has no expanding pressure, some air remains in the lungs. When saline is used to fill the lung, compliance is much greater (small pressure changes bring about large changes in volume). With saline inflation, there is little difference in the pressure-volume relationship with inflation or defla tion. This indicates that the differences seen between infla tion and deflation of air must be due to surface forces in the air-liquid interface of the alveoli.

Causes of decreased compliance: pulmonary fibrosis, pulmonary venous congestion and edema, deficiency of surfactant. Causes of increased compliance: emphysema, age.

New words

muscles – мускулы, мышцы

respiration – дыхание

inspiration – вдох

always – всегда

process – процесс

following – следующий

to be involved – быть вовлеченным

diaphragm – диафрагма

the most – наиболее

important – важный

inspiration – вдохновение

convex – выпуклый

rest – отдых

to flattens – сглаживаться

contraction – сокращение

elongating – удлинение

the thoracic cavity – грудная впадина

the thoracic – грудная клетка

the rib cage -грудное ребро

upward – вверх

outward – наружу

expanding – расширение

volume – объем

compliance – согласие

some – некоторые

to remain – остаться

saline – солончак

to fill – заполняться

Сравните следующие предложения.

1. After dinner he drank some juice. – После обеда он выпил некоторое количество сока.

2. He does not drink milk after dinner, he drinks juice. – Он не выпил молока после обеда, а выпил сок.

3. I brought some books from the library. – Я взял некоторое количество книг в библиотеке.

4. I like books. – Я люблю книги.

Зставьте some, any, no или оставьте пропуски незаполненными, ориентируясь по смыслу.

1. There is… ink in my pen.

2. Is there. snow in the treet this morning?

3. My mother likes… musik.

4. Are there. chess-players here?

5. There are. diagrams in the new book.

6. Are there. newspapers on the table?

7. Was there. water in the glass or… milk?

8. There was. soap in the box; he used wash his hands.

9. There was. soap in the box: it smells of. soap.

10. There are… letters for you on the table.

11. Do you like… apples?

12. Were there. of our teachers at the stadium?

13. There were. students of our group at the consultation yesterday.

14. Will there be… concerts at the club next month?

15. There were. yellow and green pencils on the table.

16. People need… oxygen for breathing.

17. Are there. mistakes in my dictation?

18. There are. juice in your cup.

19. My brother doesn't like. carrots.

20. I have. books now.

Answer the questions.

1. Is inspiration always an active process?

2. What muscles are involved in the mechanism of breathing?

3. What muscle is the most important of inspiration?

4. What does contraction of the external intercostals lift?