Tiny pieces, big job
Platelets are not whole cells. They are tiny pieces that break off from much bigger cells living in your bone marrow.
They are much smaller than red blood cells. Their name means little plates, because under a microscope they can look like tiny flat plates.
Most of the time, platelets just float along in your blood, smooth and round, waiting for a job.
To the rescue!
When you get a cut or a scrape, a tiny blood vessel opens up. Platelets near the spot notice right away.
They get sticky and change shape, growing little spikes like tiny arms. They stick to the edges of the cut and to each other.
Lots of platelets pile up and make a plug, like a crowd of people blocking a doorway. That starts to slow the bleeding.
Making a clot
Next, your blood makes long, thin threads called fibrin (FY-brin). The threads tangle together into a net over the plug.
The net catches red blood cells and more platelets, like a fishing net catching fish. This thick, jelly-like plug is called a clot.
A clot is a good thing at a cut. It keeps blood in and germs out.
From clot to scab
Over a day or so, the clot on top of your skin dries and hardens into a scab. A scab is like a bandage your body makes for itself.
Under the scab, new skin grows. When the new skin is ready, the scab falls off on its own.
Try not to pick it! Picking can open the cut again and slow down the healing.