ЛЕКЦИЯ № 25. Ventilation

Total ventilation (VT, minute ventilation) is the total gas flow into the lungs per minute. It is equal to the tidal volume (VT) x the respiratory rate (n). Total ventilation is the sum of dead space ventilation and alveolar ventilation.

Anatomic dead space is equivalent to the volume of the conducting airways (150 mL in normal individuals), i. e., the trachea and bronchi up to and including the terminal bronchioles. Gas exchange does not occur here. Physiologic dead space is the volume of the respiratory tract that does not participate in gas exchange. It includes the anatomic dead space and partially functional or nonfunctional alveoli (e. g., because of a pulmonan embolus preventing blood supply to a region of alveoli). In normal individuals, anatomic and physiologic dead space are approximately equal. Physiologic dead space can greatly exceed anatomic dead space in individuals with lung disease.

Dead space ventilation is the gas flow into dead space per minute. Alveolar ventilation is the gas flow entering functional alveoli per minute.

Alveolar ventilation: It is the single most important parameter of lung function. It cannot be measured directly. It must be adequate for removal of the CO₂ produced by tissue metabolism whereas the partial pressure of inspired O₂ is 150 mmHg, the partial pressure of O₂ in the alveoli is typically 100 mmHg because of the displacement of O₂ with CO₂. PAo2 cannot be measured directly.

New words

total – общее количество

ventilation – вентиляция

flow – поток

per minute – в минуту

equal – равный

the conducting – проведение

airways – воздушные пути

exchange – обмен

tract – трактат

to be measured – быть измеренным

directly – непосредственно

displacement – смещение

Перефразируйте следующие словосочетания и предложения, употребляя притяжательный падеж.

1. The handbags of these women.

2. The flat of my sister is large.

3. The children of my brother are at home.

4. The room of the boys is large.

5. The name of this girl is Helen.

6. The work of these students is interesting.

7. The dog of the brother.

8. The notebook of the teacher.

9. The friend of my friend.

10. The work of the scientist.

Переведите на английский язык, употребляя притяжательный падеж.

1. Он показал мне письмо своей сестры.

2. Она взяла коньки своего брата.

3. Дайте мне тетради ваших учеников.

4. Принесите вещи ваших детей.

5. Вчера дети нашли птичье гнездо.

6. Это семья моего друга.

7. Чья это сумка? Это сумка Тома.

8. Чьи это словари? – Это словари студентов.

9. Вы видели книгу нашего учителя?

10. Мне нравится почерк этого мальчик.

Answer the questions.

1. How minutes does it take for total ventilation?

2. Is total ventilation equal to the tidal volume?

3. Describe the process of total ventilation?

4. Is anatomic dead space equipment to the volume of the conducting airways?

5. Does gas exchange occur in trachea and bronchi?

6. What is physiological dead space?

7. What does physiological dead space include?

8. Describe the alveolar ventilation?

9. What is the most important parameter of lung function?

10. What does tissue metabolism produce?

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

Make your own sentences using possessive case (10 sentences).

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) nose; b) mouth; c) nail;

2) a) lungs; b) bronchi; c) stomach;

3) a) brain; b) rib; c) thorax;

4) a) tissue; b) bone; c) pelvis;

5) a) arm; b) shoulder; c) finger.