Full Answer
What happens to the alveolar air during inspiration and expiration?
During inspiration the end expiratory air of the previous expiration from the neighbourhood is drawn into the balloon by movement of the expiratory value. During expiration the balloon is compressed so that no dead space air may contaminate the alveolar air collected into the balloon. iii. Method of Analysis of Alveolar Air:
What is the difference between atmospheric and alveolar air?
The composition of air in the atmosphere and in the alveoli differs. In addition, alveolar air contains a greater amount of carbon dioxide and less oxygen than atmospheric air. This is no surprise, as gas exchange removes oxygen from and adds carbon dioxide to alveolar air.
What are the characteristics of inspired air?
a) i) Inspired air contains more O2, less CO2, and less water vapor then expired air. - the air in the alveoli is constantly being replaced. b) i) The release of energy by cells without the use of oxygen.
How does the composition of inspired air change during breathing?
a) The composition of the air inside the lungs changes during breathing. ii) Gaseous exchange in the alveoli causes some of the changes to the inspired air. Describe three features of the alveoli which assist gaseous exchange. [3 marks] a) i) Inspired air contains more O2, less CO2, and less water vapor then expired air.
How is alveolar air different from inspired air?
In addition, alveolar air contains a greater amount of carbon dioxide and less oxygen than atmospheric air. This is no surprise, as gas exchange removes oxygen from and adds carbon dioxide to alveolar air.
Is alveolar air inspired air?
i. Only a part of the alveolar air is replaced by inspired air . ii. There is continuous absorption of O2 from the alveolar air by pulmonary venous blood – the alveolar air, therefore, is poorer in oxygen.
What is alveolar air?
Listen to pronunciation. (al-VEE-oh-ly) Tiny air sacs at the end of the bronchioles (tiny branches of air tubes in the lungs). The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.
What is inspired air?
Inspiration (inhalation) is the process of taking air into the lungs. It is the active phase of ventilation because it is the result of muscle contraction. During inspiration, the diaphragm contracts and the thoracic cavity increases in volume. This decreases the intraalveolar pressure so that air flows into the lungs.
What is the difference between inspired and expired air?
Hint: The air that moves out of the chest during the process of expiration is called expired air while inspired air is the air that enters the lungs during the process of inspiration, provided the larynx is open.
What is the CO2 content in inspired air and alveolar air?
CO2 has a partial pressure of 0.3 mmHg in air and 40mmHg in alveoli.
What is the composition of alveolar air?
Alveolar air contains much more water vapor (6.2 percent) and carbon dioxide (5.3 percent), resulting in a dilution of nitrogen to 74.9 percent and oxygen to 13.6 percent.
What is the difference between alveoli and alveolus?
The only difference between alveoli and alveolus is that alveolus is the singular word of alveoli.
What is the basic distinction between an alveolar duct and an alveolus?
The main difference between alveoli and the alveolar sac is that the alveoli are the last end of the tract of our respiratory system which is connected to the alveolar tubes while the alveolar sac is an air space in the alveolar duct. It occurs in the lungs, which open into two or more alveoli.
What is difference between inspiration and inhalation?
Inspiration refers to inhalation—it is the flow of the respiratory current into an organism. In humans it is the movement of ambient air through the airways and into the alveoli of the lungs.
What is inspired gas?
[ ĭn-spīrd′ ] n. A gas that has been inhaled; specifically, an inhaled gas after it has been humidified at body temperature.
What is the percentage of oxygen in inspired air?
The percentage of oxygen in inhaled air is 21%.
What are the features of the alveolus?
ii) Three features from: - the wall of the alveolus is one cell thick (or very thin) - there is a moist surface to the alveoli. - there are large number of alveoli. - the air in the alveoli is constantly being replaced. b) i) The release of energy by cells without the use of oxygen. ii) In muscle cells.
What happens if the alveoli walls stick together?
The total lung volume is greater than vital capacity (some air always remains in the lungs). If not, alveoli walls would stick together, the lung would collapse. when you run, muscles in your legs use up a lot of energy. cells in the muscles need a lot of O2 very quickly.
Why do we use lime water in inspired and expired air?
To investigate the differences in composition between inspired and expired air, we use limewater because it change colour when the gas is bubbled through, from colourless to milky.
What is the meaning of alveolar air?
Definition of Alveolar Air: Alveolar air represents the air located in the respiratory part of the lungs which takes part in gas exchange with the blood in the pulmonary capillaries. Alveolar air, therefore, is a physiological quantity and does not represent the air located strictly in the anatomical alveoli.
What is the classical method of alveolar air analysis?
The classical method is to analyse alveolar air with Llyod’s modification of Haldane’s gas-analysis apparatus, which is used for analysis of respiratory gases. A measured quantity of air is admitted in the apparatus and its volume is accurately noted. The gas is then passed over caustic potash solution and its volume is noted again.
What happens to the alveolar pressure at high altitude?
At high altitude the barometric pressure falls and so the tension of gases in the inspired air and also in the alveolar air falls. Water vapour exerts a tension of 47 mmHg at all altitudes and CO 2 is continuously exerted from the body into the respiratory alveoli. As a result of this adverse combination, the PO 2 of the alveolar air falls at high altitude. Further the fall of alveolar PO 2 is disproportionately low because of extremely low O 2 tension of tissues, O 2 is absorbed very quickly from the alveoli.
What happens to the alveoli during hyperpnoea?
Hyperpnoea flushes out the alveoli with air so that the CO 2 content and CO 2 tension of the alveolar air and so of the arterial blood is diminished. This causes depression of respiration and may lead to temporary apnoea. During the depressed respiratory phase CO 2 builds up again till the alveolar PCO 2 attains its normal value and breathing is resumed. The alveolar PO 2 rises in the early phase when the PCO 2 is depressed but this has no effect on arterial saturation, which is normally 95% saturated.
What is the last part of expired air?
As expiration progresses the expired air becomes a mixture of ‘dead space’ air and alveolar air and that the last part of the expired air is pure alveolar air.
What bag is used to collect expired air?
Expired air is collected in a Douglas bag (Fig. 8.14) over a certain period of time. The sample of air is taken out from the side tube and analysed with the help of Llyod’s modification of Haldane gas analysis apparatus.
Is the alveolar air dry?
The atmospheric air, however, is dry. In calculation of tension of gases in the alveolar air, the pressure of water vapour (47 mm Hg) is to be deducted from the total pressure of gases in the alveoli which amounts to 760 mm Hg at sea-level.
