Labs / Biology
Circulation
Watch the heart pump. Blood cells run the top loop through the lungs, where they turn bright red with oxygen, then the bottom loop out to the body, where they darken as the oxygen is used up. Slide the heart rate up & down, or press the canvas to give the heart a manual squeeze.
Rate 72 bpmDelivery 0.0 cells/s
What to try
- Push the heart rate from resting to a sprint. Does the delivery rate rise in step with the beats?
- Where exactly does a cell change colour — is it a sudden switch or a gradual one as it passes through an organ?
- Turn on slow motion and watch a single beat. When does the valve open, and when do the cells surge forward?
- Why does blood need two separate loops instead of one big circle through both the lungs and the body?
- If the heart could only beat half as fast, what would the body have to do to keep the same oxygen delivery?