Definition and functions of the respiratory system, Physiologic anatomy of the respiratory system. Respiratory dynamics and work. Pulmonary ventilation: Lung volumes and capacities, Spirometry. Mechanism and mechanics of breathing, Lung surfactant, pulmonary circulation. Gas exchange and Gas transport. Oxygen Haemoglobin dissociation curve. Hypoxia and Dyspnoea. Respiratory changes in exercise and barometric changes. Control of breathing.