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 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 |
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 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
The oxy-hemoglobin dissociation curve shifts to the right in all the following conditions except:
1. Presence of 2,3-DPG | 2. Increased temperature |
3. Increased pH | 4. Increased carbon dioxide |