The figure shows a diagrammatic view of the human respiratory system with labels A, B, C, and D. Select the option that gives the correct identification, main function, and/or characteristics:
1. | B-pleural membrane- surrounds ribs on both sides to provide cushion against rubbing. |
2. | C-alveoli-thin walled vascular bag-like structures for the exchange of gases. |
3. | D-lower end of the lungs-diaphragm pulls it down during inspiration. |
4. | A trachea-long tube supported by complete cartilaginous rings for conducting inspired air. |
Two friends are eating together at a dining table. One of them suddenly starts coughing while swallowing some food. This coughing would have been due to improper movement of:
1. | diaphragm | 2. | neck |
3. | tongue | 4. | epiglottis |