Q. No.Under normal resting conditions, almost all respiratory effort is due to:
1. contraction and relaxation of diaphragm
2. elevation of rib cage
3. depression of rib cage
4. contraction of abdominal muscles
1. contraction and relaxation of diaphragm
2. elevation of rib cage
3. depression of rib cage
4. contraction of abdominal muscles
The main respiratory center in humans is located in:
1. Hypothalamus
2. Thalamus
3. Medulla oblongata
4. Pons
Consider the following statements:
| I: | The thoracic chamber is anatomically an air tight chamber. |
| II: | Any change in the volume of the thoracic cavity will be reflected in the pulmonary cavity. |
1. Both I and II are correct and II explains I
2. Both I and II are correct and I explains II
3. Both I and II are correct but II does not explain I
4. Both I and II are incorrect
The respiratory diffusion membrane is made of all the following layers except:
| 1. Alveolar epithelium | 2. Basement layer |
| 3. Vascular endothelium | 4. Surfactant |
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 |
Which occupational lung disorder can lead to cancer of lung?
1. Silicosis
2. Byssinosis
3. Bagassosis
4. Asbestosis
Which of the given three layers in the respiratory membrane is/are one-celled thick?
| I: | Alveolar epithelium |
| II: | Basement substance |
| III: | Vascular endothelium |
| 1. | Only I | 2. | Only I and II |
| 3. | Only I and III | 4. | I, II and III |
Which of the following has the highest affinity for oxygen?
1. HbS
2. HbA
3. HbF
4. Methemoglobin
When carbon dioxide combines with haemoglobin in blood, it forms:
1. Carboxyhemoglobin
2. Carbaminohemoglobin
3. Methemoglobin
4. Oxidized hemoglobin
The peripheral chemoreceptors for regulation of respiration are located:
1. adjacent to the rhythm center
2. near arch of aorta and carotid artery
3. in the walls of trachea
4. in the walls of the alveoli
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