Explore external respiration and the crucial concepts of thickness and surface area of the respiratory membrane in this informative 25-minute lecture. Delve into the definition and types of respiratory membranes, examining their epithelial cell lining and average thickness. Understand how conditions like left-side heart failure and pneumonia affect membrane thickness, and learn about thin respiratory membranes and respiratory alkalosis. Investigate the importance of surface area in respiration, including the effects of small surface area and elastase. Gain a comprehensive understanding of these vital respiratory processes through clear explanations and detailed insights.