1. Respiration
Lung Compliance

3. Change in Lung volume per unit change in transpulmonary pressure
Lung Compliance
Definition:
Change in Lung volume per unit change in transpulmonary pressure
C = Δ Volume / Δ Pressure
= 200 ml / cm H2O
TYPES: 1. Static Lung Compliance
2. Dynamic Lung Compliance

4. Lung Compliance Curves Measurement of Static Lung Compliance ( Isolated Lungs)
Two Parameters are measured to plot the Compliance Curve
1. Intra pleural Pressure ----(By using Intra esophageal balloon method)
2. Volume of air inspired or Expired-- (By Spirometer)
Hysteresis
Transpulmonary

5. Lung Compliance in Air Filled Vs Saline Filled lungs

6. Surface Tension

7. Surface Tension: Demo-soap bubbles
What will happen ?
nothing
little one to big one
big one to little one
equilibrate P2 P1

8. Surface Tension A N S W E R

9. Laplace Law
P=2T/R

10. Role of surfactant

11. Lung Surfactant

12. Surfactant Source: Type-II, Granular Pneumocytes in alveoli
(By Exocytosis
Composition: Mixture of Phospholipids
Dipalmitoyl phosphatidylcholine—62%
Phosphatidyl glycerol %
Other Phospholipids %
Neutral Lipids %
Proteins %
Carbohydrates %
Ca++

13. Functions of Surfactant
1. Stabilizes the size of the Alveoli by reducing surface tension
( Prevents overstretching as well as Collapsing)
2. Prevents Pulmonary Edema.
Deficiency at birth -> Respiratory Distress Syndrome

14. Work of Breathing Work is performed by respiratory muscles
1. Stretch the elastic tissue of the chest wall &lungs, ( Compliance work or Elastic Work) %
2. Overcome the viscosity of lungs and chest wall structures (Tissue resistance work) %
3. Overcome airway resistance
(Airway Resistance work) %

15. Work of Breathing ENERGY Expenditure:
3-5 % of the total energy expended by the body
> 50 fold during exercise provided airways are normal

16. Compliance Work

17. Dynamic Lung Compliance Curve
Airway
Resistance