erve volume is the volume of air that can be inspired in excess of the tidal volume. Expiratory reserve volume is the extra an that can be expired after a normal tidal expiration.
Residual volume is the volume of gas that re lungs after maximal expiration (average human = 1,2 L).
Lung capacities are comprised of two or more of the lung volumes. Total lung capacity is the volume of gas that can be con tained within the maximally inflated lungs (average human = 6 L).
Vital capacity is the maximal volume that can be expelled after maximal inspiration (average human = 4,8 L).
Functional residual capacity is the volume remaining in the lungs at the end of a normal tidal expiration (average luman = 2,2 L).
Inspiratory capacity is the volume that can be taken into the lungs after maximal inspiration following expiration of a normal breath. Residual volume can not be directly measured by spirometry. Because FRC and TLC include the residual capacity, they can not be directly measured by spirometry either. Helium dilution techniques are used to determine these capacities. A forced vital capacity is obtained when a subject inspires maximally and then exhales as forcefully and as completely as possible. The forced expiratory volume (FEV1) is the volume of air exhaled in the first second. Typically, the FEV1 is approximate 80% of the FVC. In obstructive lung diseases, such as bronchial asthma, the FEV1 is reduced much more that the FVC, producing a to FEV1 / FVC. In restrictive lung diseases, such as pulmonary fibro-sis, both the FEV1, and the FVC are reduced. This characteristically produces a normal or increased FEV1/ FVC.
GAS LAWS AS APPLIED TO RESPIRATORY PHYSIOLOGY: Dalton's Law: In a gas mixture, the pressure exerted by each gas is independent of the pressure exerted by the other gases.
A consequence of this is as follows: partial pressure = total pressure x fractional concentration. This equation can be used to determine the partial pressure of oxygen in the atmosphere. Assuming that the total pressure (or barometric pressure, PB) is atmospheric pressure at sea level (760 mmHg) and the fractional concentration of O2 is 21%, or 0,21: P02 = 760 mmHg ч 0,21 = 160 mmHg. As air moves into the airways, the partial pressures of the vari ous gases in atmospheric air are reduced because of the addi tion of water vapor (47 mmHg). Henry's Law states that the concentration of a gas dissolved in liquid is proportional to its partial pressure and its solubility coef ficient (Ks). Thus, for gas X, [X] = Ks ч Px
Fick's Law states that the volume of gas that diffuses across a barrier per unit time is given by:
Vgas = YxDx(P1 – P2)
where A and T are the area and thickness of the barrier, P1 and P2 are the partial pressures of the gas on either side of the barrier and D is the diffusion constant of the gas. D is directly proportional to the solubility of the gas and inversely proportional to the square root of its molecular weight.
New words
lung – легкое
volume – объем
equal – равный
the maximal – максимальный
tidal – вдыхаемый и выдыхаемый
inspired – вдохновленный
expected – ожидаемый
normal – нормальный
breath – дыхание
average – среднее число
human – человек
reserve – зарезервировать
residual – oстаточный
helium – гелий
dilution – растворение
techniques – методы
to be used to – использовать
to determine – определять
capacities – возможности
Поставьте слова в следующих предложениях во множественное число.
1. This room is very large.
2. There is a match in the box.
3. Has this lady a knife?
4. There is a man and a woman in the street.
5. This lady is that gen tleman's wife.
6. This shoe is too large for my foot.
7. The child is sitting on a bench.
8. My tooth is white.
9. This key is made of steel.
10. A potato is a vegetable and a cherry is a fruit.
11. This is my friend's study.
12. What is that child's name?
13. The cat has caught a mouse.
14. There was a lady, a gentleman, a boy and a girl in the room.
15. In the farm-yard we could see an ox, a sheep, a cow and a goose.
16. Is worker an Englishman or a German?
17. He is a Frenchman.
18. Why don't you eat this potato?
19. This strawberry is still green.
20. The withered leaf has fallen to the ground.
21. Can you see a bird in that tree?
22. Does your tooth still ache?
23. I held up my foot to the fire to warm it.
24. His child studies very well.
25. This man works at the office.
26. There is a new house in our street.
27. This story is very interesting.
28. I have hurt the foot.
29. The wolf has been shot.
30. He keeps his toy in a box.
31. Put this knife on that table.
32. I see a pupil.
Притяжательный падеж существительных / (Possessive case)
The child's toys – The children's toys
The boy's books – The boys' books
Перефразируйте следующие словосочетания и предложения, употребляя притяжательный падеж.
1. The room of my friend.
2. The questions of my daughter.
3. The wife of my brother.
4. The table of our teacher.
5. The poems of Shakespeare.
6. The voice of this girl.
7. The new club of the workers.
8. The letter of Pete.
9. The car of my parents.
10. The life of this woman.
Answer the questions.
1. How many lung volumes are there?
2. Are the lung volumes added together?
3. How can inspiratory reserve volume be inspired?
4. Can inspiratiry reserve volume be expired after a normal tidal expiration?
5. What is residual volume?
6. How are lungs capacities be composed?
7. Is vital capacity the maximal volume?
8. What is the functional residual capacity?
9. What is the inspiratory capacity?
10. Can residual volume be directly measured by spirometry?
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) volume; b) head; c) lung;
2. a) air; b) breathing; c) hot;
3. a) stomach; b) bronchi; c) lungs;
4. a) nose; b) trachea; c) finger;
5. a) eye; b) alveoli; c) bronchi.
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?