Ever wonder why the heart sounds the way that it does? Opening and closing of heart valves makes the heart rhythm come alive with its lub dub beats... Rishi is a pediatric infectious disease physician and works at Khan Academy.
More free lessons at: http://www.khanacademy.org/video?v=-4...
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 in seeking it because of something you have read or seen in any Khan Academy video.