Click4Biology: 6.4 Gas exchange


Gas exchange

6.4.1 Ventilation, gas exchange and cell respiration.

6.4.2 The need for a ventilation system.

6.4.3 Features of the alveoli.

6.4.4 Structure of the ventilation system.

6.4.5 Mechanism of ventilation.

6.4.1 Distinguish between ventilation, gas exchange and cell respiration.(2)

1. Ventilation:

2. Gas Exchange:

This is the diffusion of gases (oxygen and carbon dioxide)

There are two sites for gas exchange



3. Cell Respiration



6.4.2 Explain the need for a ventilation system.(3)




6.4.3 Describe the features of alveoli that adapt them to gas exchange.(2)








6.4.4 Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli.(1).


(a) Trachea

(b) Cartilage ring support

(c) Bronchi (plural) Bronchus (single)

(d) Lung

(e) Heart

(f) Sternum

(g) Rib cage

(h) Bronchioles (j) Alveoli (k) Diaphragm




6.4.5 Explain the mechanism of ventilation of the lungs in terms of volume and pressure changes caused by the internal and external intercostal muscles, the diaphragm and abdominal muscles.(3)