Q. No.An increase from pH 7.2 to pH 7.4 around hemoglobin causes:
1. Hemoglobin to release all bound oxygen molecules.
2. An increase in the affinity of hemoglobin to bind oxygen molecules.
3. Hemoglobin to denature.
4. An increase in the binding of H+ by hemoglobin.
1. Hemoglobin to release all bound oxygen molecules.
2. An increase in the affinity of hemoglobin to bind oxygen molecules.
3. Hemoglobin to denature.
4. An increase in the binding of H+ by hemoglobin.
The diaphragm and external intercostal muscles are ________ when expiration occurs.
| 1. | contracted |
| 2. | relaxed |
| 3. | flexed |
| 4. | both relaxed (diaphragm) and flexed (intercostal muscles) |
What is the primary function of the Pneumotaxic Center in the regulation of respiration in human beings?
| 1. | It increases the rate and depth of breathing |
| 2. | It decreases the rate of and depth of breathing |
| 3. | It controls the “switch off’ point of inspiration |
| 4. | It initiates the “Herring-Breur” reflex |
Respiration is under neural and chemical regulation. The receptors for chemical regulation are located in the:
| 1. | walls of the carotid and aortic arteries and in the medulla oblongata. |
| 2. | walls of the carotid and aortic arteries only. |
| 3. | medulla oblongata and in the walls of the superior and inferior vena cavas. |
| 4. | walls of the carotid and aortic arteries and in the walls of the superior and inferior vena cavas. |
At lungs carbon dioxide diffuses out of the pulmonary capillaries into the alveoli. As a result hemoglobin’s ability to bind to oxygen would:
| 1. | be unstable | 2. | stay the same |
| 3. | decrease | 4. | increase |
Breathing is best described as
| 1. | Utilisation of O2 by the cells for catabolic reaction. |
| 2. | Transport of gases by the blood. |
| 3. | The movement of air into and out of the lungs. |
| 4. | Diffusion of gases across alveolar membrane |
Partial pressure of \(CO_2\) in alveoli of lungs:
| 1. | Is equal to that in the deoxygenated blood. |
| 2. | Is more than that in the deoxygenated blood. |
| 3. | Is less than that in the deoxygenated blood. |
| 4. | Is more than that of \(CO_2\) in alveoli. |
The figure given below shows a small part of the human lung where exchange of gases takes place. In which one of the options given below, the one part A, B, C or D is correctly identified along with its function?
| 1. | A – Alveolar cavity – main site of exchange of respiratory gases |
| 2. | D – Capillary wall – exchange of O2 and CO2 takes place here |
| 3. | B – Red blood cell – transport of CO2 mainly. |
| 4. | C – Arterial capillary – passes oxygen to tissues |
Given below a diagram of a section of an alveolus with a pulmonary capillary. Which of the following is a correct statement for diffusion of gases?
| 1. | Diffusion of O2 and CO2 from A to B or B to A takes place with the same rate. |
| 2. | O2 will diffuse faster from A to B than CO2 from B to A |
| 3. | Only O2 will diffuse from A to B not CO2 from B to A |
| 4. | Only CO2 will diffuse from B to A, not O2 from A to B |
| Column-I | Column-II | ||
| (a) | Tidal volume | (i) | 2500-3000 mL |
| (b) | Inspiratory Reserve | (ii) | 1100-1200 mL volume |
| (c) | Expiratory Reserve | (iii) | 500-550 mL volume |
| (d) | Residual volume | (iv) | 1000-1100 mL |
| Options: | (a) | (b) | (c) | (d) |
| 1. | (iii) | (ii) | (i) | (iv) |
| 2. | (iii) | (i) | (iv) | (ii) |
| 3. | (i) | (iv) | (ii) | (iii) |
| 4. | (iv) | (iii) | (ii) | (i) |
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