Health and medicine: People and plants

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.

Health and medicine

The medical world can be a confusing place. Patients, their families, and even students entering health fields might feel overwhelmed by the large vocabularies and complicated explanations. We hope to make understanding the medical world a bit easier. Look around! These videos do not provide medical advice and are for informational purposes only. The videos are not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read or seen in any Khan Academy video.

Respiratory system introduction

Did you know that your right lung is larger than your left? That’s because the majority of your heart is on the left side of your body, and your left lung is slightly smaller to accommodate it. The lungs take in oxygen and help you breathe out carbon dioxide. Humans have an intricate respiratory system, with hundreds of millions of tiny air sacs called alveoli, where all of the magic happens. These videos will introduce you to the lungs, and show how they help you survive.

Topic: Science

Learn about all the sciences, from physics, chemistry and biology, to cosmology and astronomy, across hundreds of videos, articles and practice questions.