ЛЕКЦИЯ № 23. Respiratory system

The respiratory system is structurally and functionally adapt ed for the efficient transfer of gases between the ambient air and the bloodstream as well as between the bloodstream and the tissues. The major functional components of the res piratory system are: the airways, alveoli, and blood vessels of the lungs; the tissues of the chest wall and diaphragm; the systemic blood vessels; red blood cells and plasma; and respi ratory control neurons in the brainstem and their sensory and motor connections. LUNG FUNCTION: provision of O₂ for tissue metabolism occurs via four mechanisms. Ventilation – the transport of air from the environment to the gas exchange surface in the alveoli. O₂ diffusion from the alveolar air space across the alveolar-capillary membranes to the blood.

Transport of O₂ by the blood to the tissues: O₂ diffusion from the blood to the tissues.

Removal of CO₂ produced by tissue metabolism occurs via four mechanisms. CO₂ diffusion from the tissues to the blood.

Transport by the blood to the pulmonary capillary-alveolar membrane.

CO₂ diffusion across the capillary-alveolar membrane to the air spaces of the alveoli. Ventilation – the transport of alveolar gas to the air. Functional components: Conducting airways (conducting zone; anatomical dead space).

These airways are concerned only with the transport of gas, not with gas exchange with the blood.

They are thick-walled, branching, cylindrical structures with ciliated epithelial cells, goblet cells, smooth muscle cells. Clara cells, mucous glands, and (sometimes) cartilage.

Alveoli and alveolar septa (respiratory zone; lung parenchyma).

These are the sites of gas exchange.

Cell types include: Type I and II epithelial cells, alveolar macrophages.

The blood-gas barrier (pulmonary capillary-alveolar membrane) is ideal for gas exchange because it is very thin (‹0,5 mm) and has a very large surface area (50-100 m2). It consists of alveolar epithelium, basement membrane interstitium, and capillary endothelium.

New words

respiratory – дыхательный

structurally – структурно

functionally – функционально

adapted – приспособленный

efficient – эффективный

transfer – перемещение

gases – газы

ambient – окружающий

air – воздух

bloodstream – кровоток

airways – воздушные пути

alveoli – альвеолы

blood vessels – кровеносные сосуды

lungs – легкие

chest – грудь

diaphragm – диафрагма

the systemic blood vessels – системные кровеносные сосуды

red blood cells – красные кровяные клетки plasma – плазма

respi ratory control neurons – дыхательные нейроны контроля

brainstem – ствол мозга

sensory – сенсорный

motor connections – моторные связи

ventilation – вентиляция

transport – транспортировка

environment exchange – окружающая среда

surface – поверхность

Запомните!

Един. ч. – множ. ч.

this is – these are

that is – those are

there is – there are

it is – they are

Поставьте слова в следующих предложениях во множественное число.

1. This is a star.

2. This is a boy.

3. This is a baby.

4. That is a plate.

5. That is a flower.

6. That is a bookshelf.

7. Is this a sofa?

8. Is this a bookcase?

9. Is this a man?

10. Is that a ball?

11. Is that a train?

12. Is that a plane?

13. Is the window open?

14. Is the door closed?

15. Is the boy near the window?

16. That is not a king.

17. That is not a queen.

18. That is not a bus.

19. That isn't a mountain.

20. That isn't a goose.

21. This isn't a mouse.

22. It is a sheep.

23. It is a cigarette.

24. It is a cat.

25. It is not a girl.

26. It isn't a bag.

27. It isn't a tree.

28. It is not a bad egg.

29. It is a good egg.

30. Is that a flower?

31. This man is an engineer.

32. That woman is my sister.

33. This child is my son.

34. That goose is big.

35. This mouse is white.

36. This man is a doctor.

37. That woman is my cousin. She is a teacher

38. That girl is my niece. She is a pupil.

39. This girl has a blue sweater.

40. This boy has a good coat.

41. My uncle has a large flat.

42. There is a table in the room.

43. I have a good pen. My pen is in my pocket.

44. There is a flower in the vase.

45. This child's foot is sore.

Answer he questions.

1. What is the respiratory system structurally adopted?

2. What does the respiratory system transfer?

3. What are the most major lung functions?

4. What do we breath in?

5. What do we breath out?

6. How is the oxygen delivered to the organs?

7. How is oxygen delivered to the organs?

8. What is metabolism?

9. What are the functional components?

10. What do cell types include?

Make the sentences of your own using the new words (10 sentences).

Find plural and single in the text.

Find one word, which is a little bit different in meaning from others (найдите одно слово, которое немного отличается от других по смыслу):

1. a) palm; b) blood; c) vessel;

2. a) leg; b) tissue; c) metabolism;

3. a) airways; b) alveoli; c) arm;

4. a) intestines; b) cell; c) membrane;

5. a) oxygen; b) breath; c) carbon.