Red Blood Cell

human body · blood · oxygen

Shaped like tiny discs. Red blood cells look like little flattened doughnuts without holes in the middle. This special shape helps them squeeze through the tiniest blood vessels in your body to deliver oxygen right where it's needed.

Your superdelivery system. Red blood cells pick up oxygen in your lungs and carry it through your bloodstream to every part of your body. Without them, your muscles, brain, and organs wouldn't get the fuel they need to work.

Constantly on patrol. Your body makes millions of new red blood cells every single day to replace the ones that wear out. A single red blood cell can live about 120 days before your body recycles it.

Fish do it differently. While you absorb oxygen through your lungs, fish use their gills to pick up oxygen from water. But fish red blood cells work the same way yours do, delivering that oxygen throughout their bodies.

Most common blood cell. Red blood cells outnumber all your other blood cells by a huge amount. You have trillions of them working together right now to keep you healthy and active.