My Amazing Body 3-minute video · ages 4-8 · free coloring page
How does a scab help my cut get better?
You fall down and scrape your knee. A day later, there is a hard, dark crust on it, called a scab. What is a scab, and how does it help your cut get better?
3 min
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Free coloring page
The scene from the video as a coloring page, plus the three-sentence answer, the experiment, and a QR code back to this page. One sheet, US Letter, black and white.
The answer in three parts
Why?
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Your skin is like a wall, and a cut is a hole in that wall.
The wall keeps the good things in, like your blood, and the bad things out, like dirt and germs. Through a hole, blood can leak out and germs can get in. Your body has to fix it, fast!
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Tiny platelets rush over and plug the hole.
Platelets float in your blood all the time, waiting. They stick to the edges of the hole and to each other, and pile up. In just a few minutes they make a soft plug, and the bleeding stops.
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Sticky threads hold it tight, and the top dries hard.
Your blood makes sticky threads, thinner than a spider's web. They weave over the platelets like a net. This is called a clot. The top of the clot touches the air, so it dries out and gets hard. That is the scab, a lid your body made by itself!
For grown-ups: Under the lid, white blood cells clean up and gobble any germs that sneaked in, while new skin grows in from the edges a tiny bit every day. A scab that feels tight and itchy usually means it is healing. When you get a cut, tell a grown-up, wash it gently with clean water and cover it with a bandage; if a cut is deep, or will not stop bleeding, get a grown-up right away.
How a scab gets made
- Cuta hole in the skin wall
- Plugplatelets pile up
- Netsticky threads hold tight
- Scabthe top dries hard
A tiny experiment
Try it!
Be a scab watcher
You need: a scrape that is already healing
- Look at the scab every day. Just look, don't pick!
- Does it feel tight or itchy? That usually means it is healing.
- When it falls off by itself, look at the new skin. It is pink at first. Watch it slowly turn to your own color.
What happened? Under the scab, new skin grows in from the edges, a tiny bit every day, until it covers the whole spot.
Did you know?
Please don't pick your scab! If you pull the lid off too soon, the hole is open again, and your body has to start all over.
When you get a cut, tell a grown-up. Wash it gently with clean water, and cover it with a bandage.
Your guide in this video
I'm Patch, a tiny platelet. I live in your blood!
Patch is a pale golden platelet in a blue hard hat. Fluffy white blood cells help Patch keep the germs out.
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