Mechanism of Breathing - Overview

Description:

Mechanism of respiration involves the alternate expansion and contraction of chest cavity called respiratory movements.

Breathing is a process which involves two stages −

• Inspiration − Process in which atmospheric air is drawn inside the body.

• Expiration − Process in which the alveolar air is released out.

The respiratory frequency is about 12 to 16 times per minutes in adult man. The movement and exchange of gases between lungs and the atmosphere occurs due to formation of pressure gradient.

Respiratory membrane

• Alveolar epithelium and capillary endothelium along with their basement membranes and intestinal fluid are collectively called the respiratory membrane.
• Gaseous exchange occurs across the respiratory membrane.
• Each alveolus is lined by squamous epithelial cells and is highly glandular and vascular.
• Blood and air in the alveoli are separated by alveolar epithelium and capillary epithelium.