It is necessary that lungs must be present in anatomically air-tight chamber because:
| 1. | we cannot directly alter the pulmonary volume |
| 2. | our lungs are not made of any elastic tissue |
| 3. | the pleural cavity always has a positive pressure with respect to pulmonary pressure |
| 4. | the partial pressure of oxygen in atmosphere is less than that in the alveoli |
The conducting part of the human respiratory system is not involved in:
| I: | clearing inhaled air from foreign particles |
| II: | humidifying the exhaled air |
| III: | bringing the air to a temperature higher than body temperature |
| 1. | Only I | 2. | Only II and III |
| 3. | Only I and II | 4. | I, II and III |
The major mode of transport of carbon dioxide in human body is:
| 1. | in combination with hemoglobin |
| 2. | in dissolved state in plasma |
| 3. | as carboxyhemoglobin |
| 4. | as bicarbonate |
The formation of oxy-hemoglobin at the alveoli is favored by all the following except:
| 1. High pO2 | 2. Low pCO2 |
| 3. Lower H+ ion concentration | 4. Higher temperature |
Which of the following equations regarding the calculation of pulmonary capacities would be correct?
| 1. | IC = IRV – TV | 2. | EC = VC – IRV |
| 3. | VC = ERV + IRV | 4. | TLC = VC – RV |
The partial pressure of oxygen in oxygenated blood is about:
| 1. 104 mmHg | 2. 100 mmHg |
| 3. 95 mmHg | 4. 40 mmHg |
The volume of thoracic chamber in the antero-posterior axis can be increased by:
1. Contraction of diaphragm
2. Relaxation of diaphragm
3. Contraction of external intercostals
4. Contraction of internal intercostals
The alveoli are lined with:
1. Simple cuboidal epithelium
2. Pseudo-stratified columnar ciliated epithelium
3. Transitional epithelium
4. Simple squamous epithelium
The binding of carbon dioxide to hemoglobin:
I: is related to the partial pressure of carbon dioxide
II: is affected by the partial pressure of oxygen
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect