During Expiration, the pressure within the [[Pleural cavity and membranes - Anatomy & Physiology|Pleural Cavity]] increases to greater than that of the external environment, in orfer to expel air from the [[Lungs - Anatomy & Physiology|lungs]]. This is achieved by decreasing the lung volume, caused by relaxation of Inspiratory Muscles:
+
During Expiration, the pressure within the [[Pleural cavity and membranes - Anatomy & Physiology|Pleural Cavity]] increases to greater than that of the external environment, in order to expel air from the [[Lungs - Anatomy & Physiology|lungs]]. This is achieved by decreasing the lung volume, and is brought about by relaxation of Inspiratory Muscles:
**Dome of the [[Diaphragm - Anatomy & Physiology|Diaphragm]] is pushed back by the intrathoracic pressure.
**Dome of the [[Diaphragm - Anatomy & Physiology|Diaphragm]] is pushed back by the intrathoracic pressure.
**[[Ribs and Sternum - Anatomy & Physiology|Ribs]] recoil back to their original position.
**[[Ribs and Sternum - Anatomy & Physiology|Ribs]] recoil back to their original position.