The heart
Heart · cor
A fist-sized double pump that pushes blood to your lungs and to everywhere else, without a break.
What it does
Your heart is really two pumps side by side. The right side sends tired, oxygen-poor blood a short distance to the lungs. The left side, thicker and stronger, pushes fresh blood out through the aorta to every other part of you. Four one-way valves keep the flow moving forwards, and each beat is set off by the heart's own built-in electrical pacemaker.
Surprising fact
Your heart beats about 100,000 times a day. That adds up to more than two and a half billion beats over an average life, with no days off.
Why it matters
Every cell you own needs a steady supply of oxygen, and the heart is the only thing delivering it. When you feel your pulse at your wrist or neck, you are feeling the pressure wave from the left side's last squeeze.
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.