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
The basic rhythm of breathing is controlled by:
1. peripheral chemoreceptors
2. dorsal respiratory group of the medullary rhythmicity center
3. ventral respiratory group of the medullary rhythmicity center
4. pneumotaxic area
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
1. | Tidal volume in a healthy human adult | About 500 ml |
2. | Partial pressure of oxygen in oxygenated blood | 159 mm Hg |
3. | Resting respiratory rate in a healthy adult | 12 to 16 per minute |
4. | Percent of carbon dioxide transported as bicarbonate in the blood | 70 |
The most negative pressure at the end of normal inspiration would be:
1. alveolar | 2. tracheal |
3. partial | 4. pleural |
Which of the following will bring about inhalation in human beings?
I. Contraction of diaphragm
II. Contraction of internal intercostals
III. Contraction of external intercostals
1. | Only I and II | 2. | Only I and III |
3. | Only II and III | 4. | I, II and III |