Question

3922
The adjoining diagram represents the organs of human thorax.
Guidelines for parts 1 to 7 are indicated below:
1. Trachea,
2. Bronchiole,
3. Bronchus
4. Rib
5. Pleural membrane
6. Thoracic cavity,
7. Diaphragm.
Study the diagram and answer these questions:
© What are the functions of parts 1,5 and 7?
(1) Why should the lining of alveoll be moist?
() What are the positions of diaphragm at the time of inspiration and expiration?​

Answer 1

Answer:

(1) Adaptations of the alveoli:

Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. A large diffusion gradient - breathing ensures that the oxygen concentration in the alveoli is higher than in the capillaries so oxygen moves from the alveoli to the blood.

(2) The affected side of the diaphragm moves upwards during inspiration, and downwards during expiration.