Basic Structure of the lung a tube= Airway (Trachea-Bronchi - B bronchioles) VD NO GAS EXCHANGE DEAD SPACE a thin walled Sac alveolus GAS EXCHANGE OCCURS HERE Blood Vessels Formula: Total Ventilation= Dead Space Alveolar Space Vr=VD+Ⅴ D12 Basic Structure of the Lung VD A tube = Airway (Trachea – Bronchi – Bronchioles) NO GAS EXCHANGE DEAD SPACE A thin walled Sac = Alveolus Blood Vessels GAS EXCHANGE OCCURS HERE VA Formula: Total Ventilation = Dead Space + Alveolar Space VT = VD + VA