5.5.1 List the features of alveoli that adapt them to gas exchange

(large total surface area, a wall consisting of a single layer of flattened cells, a moist lignin g and a dense network of capillaries)

5.52 State the difference between ventilation, gas exchange and cell respiration.

5.5.3 Explain the necessity for a ventilation system.

(needed to maintain concentration gradients in the alveoli)

5.5.4 Draw a diagram of the ventilation system including trachea, bronchi, bronchioles and lungs.

5.5.5 Explain the mechanism of ventilation in human lungs including the action of the internal and external intercostals muscles, the diaphragm and the abdominal muscles