Physiology 2130 Lecture Notes - Lecture 10: Pulmonary Surfactant, Breathing, Intrapleural Pressure

• School: Western University
• Department: Physiology
• Course: Physiology 2130
• Professor: Christine Bell

Document Summary

Transport of o2 from air into blood. Removal of co2 from blood into air. Mechanisms of pulmonary ventilation (breathing), lung volumes, diffusion and transport of gases, and the regulation of ventilation. Lungs are located in thoracic cavity, surrounded by rib cage and diaphragm. Airway consists of nasal cavity + mouth that joins at the pharynx. Order of pathway: pharynx larynx (aka voice box) trachea left and right bronchi bronchioles alveoli (sites of gas exchange) Pulmonary artery delivers deoxygenated blood to the lungs via branching into a dense network of capillaries around each alveolus. Structure of capillaries and blood flow ensures maximal gas exchange: thin epithelial walls, large cross-sectional area, low blood velocity. In capillaries, oxygen diffuses into blood while co2 diffuses out, then blood flows back to left side of the heart via pulmonary vein. There are ~300 million alveoli in a healthy human lung. Alveolar walls are one cell thick and composed of alveolar epithelial cells (type i cells)