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.
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 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 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) |