Do you know the muscles involved and the process that takes place that allows you to inhale and exhale? This video lecture will teach you about how muscle contraction and lung recoil actually help the lungs change their volume with every...

Learn more about photosynthesis and cellular respiration through a classic story: Jack and the Beanstalk. Rishi is a pediatric infectious disease physician and works at Khan Academy.

Find out exactly why air goes in and out of the lungs. [12:59]

Every time you take a breath, oxygen makes it way into your lungs. Follow along on that journey! Rishi is a pediatric infectious disease physician and works at Khan Academy. [9:36]

Follow the path of an oxygen molecule as it makes its way from your mouth down to an alveolus! This video explores teh bronchial tree. [12:46]