Ventilation - Anatomy & Physiology

()Map CARDIORESPIRATORY SYSTEM (Map)

Introduction

Ventilation is the movement of air into and out of the lungs. Air moves from high pressure to low pressure with the rate of flow being proportional to the pressure difference. As environmental pressure is generally constant, the respiratory system must change it's internal pressure to maintain air flow.

Inspiration

• During Inspiration, the pressure within the Pleural Cavity drops to less that the pressure of the external environment.
• This is achieved by increasing the lung volume, brought about by the Inspiratory Muscles:
  • Diaphragm - flattens
  • Intercostal muscles