Tusomesasa.

Describe the process of expiration in man.(9marks)

Suggested resposponses

The external intercostal muscles relax; while the internal intercostal muscles contract; the ribcage moves inwards; and downwards; The diaphragm muscles relax;and the diaphragm assumes a dome shape; volume in the thoracic cavity decreases; and pressure increases; air is forced out of the lungs and the lungs deflate;