Platelets & Blood Clotting | Biology | FuseSchool

Do you remember tripping over as a kid and cutting your knee? And then like magic the bleeding suddenly stops? Have you ever wondered why this happens?

Our body is very clever and produces substances to seal off the open wound.

In this video we are going to look at how and why blood clots.

Clotting prevents us from bleeding to death, and also protects us from nasty disease-causing organisms, called pathogens, entering our body.

When we injure ourselves, we can damage the blood vessels just below our skin. This can cause blood to either leak into our tissue and form a bruise, or, if the skin is broken to openly bleed.

To prevent these horrible things happening, blood clotting occurs.

So let’s have a look at how this happens.

Starting with platelets. These are tiny cell fragments that float around in our blood.

When a blood vessel is damaged, collagen is exposed. This collagen exposure attracts platelets to the injured area. The platelets then stick together to form a plug.

They’ve quickly built a little barrier that stops us from losing too much blood. However, this platelet plug isn’t that strong. So it needs to be made stronger.
A protein called fibrin does exactly that.

In our blood there are soluble fibrinogen proteins. At a wound, these soluble fibrinogen proteins are exposed to outside chemicals that aren’t normally found in blood vessels. Like with the collagen and platelets, this exposure causes the fibrinogen proteins to turn into sticky fibrin fibres.

The fibrin fibres form a mesh, holding all the platelets together and making a much stronger clot.

More platelets, red blood cells and other components in our blood, all get stuck in the mesh making it even stronger. This clot stops more blood escaping the body. And also prevents nasty pathogens entering our body from the outside.

The clot develops into a scab, which protects the wound as it heals and new layers of skin form underneath. So really, all a scab is is just platelets trapped in the fibrin mesh!

When the new skin is fully formed, the scab will fall off, revealing the lovely brand new skin underneath.

Remember that I said the exposure to collagen causes the platelets to stick together? And the exposure to outside chemicals causes the fibrinogen to turn into sticky fibrin?

Both the platelets and the fibrin only become sticky AFTER the exposure. This means that in a normal, healthy blood vessel they won’t randomly cause clots.

So from this video, you should understand the magic of blood clotting. Platelets are first to the scene closely followed by fibrin fibres. Our blood clots so that we don’t lose a lot of blood and don’t let lots of nasty pathogens into our body if we cut ourselves.

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[catelynrossetto]

Thanks. Just showed this to my 6 year old daughter after getting a cut in her hand. Now she's looking at the cut and saying, "You're doing a great job platelets!" ☺️

[peachblossom]

FINALLY a video from this channel that has actual audible pronunciation OMG

[ianhuang]

Finally a video about blood clotting I can finally understand.

[stephanylara]

A simple explanation, just what I needed.

[safajannat]

Can u make a detailed video on blood clotting where the function of thrombokinase, prothrombin , fribrinogen and fibrin are given properly

[socialtech]

You elaborate it in a very simple way!! Thank you

[lehaswinipalla]

This is exactly what I was looking for. Thank you so much !!!!

[jordand.]

Thank you, explained in a very simple way and straight to the point.

[avinashjohnson]

You have help me revise for my test thank you so much 😊

[meganlim]

When there’s an open wound, platelets will release chemicals that cause a soluble fibrinogen protein to convert into a insoluble fibrin and insoluble mesh. This will allow the blood cells to trap and therefore forming a clot. When the clot dries, it will form a scab that prevents bacteria from entering the wound .

[nehavathana]

thank you so much for sharing thiss...its very helpfull..

[irenevillatoro]

You explain simply and easy thank you so much ☺️

[fuhkuhmi]

What a fantastic mechanism our body has it surprises me everyday God has created us so finely 🙏

[ahm]

That's what I was exactly looking for! Many thanks.

[DanDanCrafts]

Wow now I understand this in only 3 MINUTES!?!?!? This is insane and may be really helpful

[Queen-ijix]

What is the difference between hemostasis, blood clotting and coagulation?
All 3 processes are quite similar which makes it confusing to understand

[m.a.p.g.]

Thank you from a #TTP (Thrombotic thrombocytopenic purpura) patient.

[peterleclair]

Is the same thing done after mass surgery for triple by pass.

[youtuber]

Can i get a heart for my fav teaching channel ❤❤❤❤

[sumaiyachowdhury]

Thanks it was helpful. Give more educational videos