Dead Space Area where gas exchange cannot occur Includes most of airway volume Anatomical dead space(150 ml) Airways Physiological dead space anatomical non functional alveoli
11 Dead Space • Area where gas exchange cannot occur • Includes most of airway volume • Anatomical dead space (=150 ml) – Airways • Physiological dead space = anatomical + non functional alveoli
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 D
12 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
Similar Concept: Physiological Dead spac Healthy Lungs: Anatomical Dead Space = Airways(constant) Diseased lungs: Physiological Anatomical Dead Space Dead Space 十 Additional Dead Space Blocked Vessel
13 Physiological = Anatomical Dead Space Dead Space + Similar Concept: Physiological Dead Space Diseased lungs: Healthy Lungs: Blocked Vessel Additional Dead Space • Anatomical Dead Space = Airways (constant) VA VD
2. Lung Compliance Lung compliance (Cu is a measure of the elastic properties of th ne lung is a reflection of lung distensibility 4
14 2. Lung Compliance • Lung compliance (CL ) • is a measure of the elastic properties of the lung, • is a reflection of lung distensibility
Elasticity Tendency to return to initial size after distension High content of elastin proteins Very elastic and resist distension Recoil ability Elastic tension increases during inspiration and is reduced by recoil during expiration 15
15 Elasticity • Tendency to return to initial size after distension. • High content of elastin proteins. – Very elastic and resist distension. • Recoil ability. • Elastic tension increases during inspiration and is reduced by recoil during expiration