A minimal amount of pleural fluid present in the pleural cavity:
| 1. | provides a medium for the exchange of respiratory gases |
| 2. | reduces friction between the visceral and parietal pleurae |
| 3. | provides lubrication for movements of the diaphragm |
| 4. | permits the exchange of electrolytes during respiration |
During deglutition, the food is prevented from entering into the larynx by the cartilaginous:
| 1. epiglottis | 2. glottis |
| 3. aryepiglottic fold | 4. laryngeal prominence |
The alveoli are lined with:
1. Simple cuboidal epithelium
2. Pseudo-stratified columnar ciliated epithelium
3. Transitional epithelium
4. Simple squamous epithelium
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 |
| I: | P is an incomplete cartilaginous ring seen only in trachea and principal bronchus. |
| II: | Q is the point where the trachea divides into a right and left primary bronchus and corresponds to the level of 5th thoracic vertebra. |
| III: | R shows the double-layered pleura where the outer pleural membrane is in close contact with the thoracic lining. |
| IV: | S is pleural cavity with minimal amount of pleural fluid which reduces friction on the lung surface. |
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 |
During expiration, the diaphragm and external intercostal muscles are:
1. contracted
2. relaxed
3. flexed
4. both relaxed (diaphragm) and flexed (intercostal muscles)
A measure of the amount of air a person inhales during a normal breath is:
| 1. inspiratory reserve volume | 2. vital capacity |
| 3. total lung capacity | 4. tidal volume |
The amount of air that remains in a person's lungs after fully exhaling is known as:
| 1. tidal volume | 2. expiratory reserve volume |
| 3. vital capacity | 4. residual volume |