How Long Would It Take A Glass Of Blood To Turn Into A Jelly Blob?

[joko]

weird question i know.

years ago i has a bad nose bleed and had no choice but to let it fill a glass.

i put the glass down and when i went back to it, it had congealed completely and was like a rounded jelly blob, wobbling around in the glass.

it was kind of the texture of those fruit jelly cube packets, before you make it with boiling water.

im just wondering how long it would have taken for it to turn into that state?

i know blood in a wound will start to congeal in about 30 seconds, but this was about quarter of a pint in a half pint glass, so most of the blood was not 'touching' the air, like it would be if falling from a wound, so i assume it'd take much longer ...?

anyone know?

thanks :)

[theprof]

On looking at some of the answers provided to this question, I'll begin by saying that for those that want to be lost in the science, just look up " in vitro blood coagulation". The " in vitro" can be translated as "in glass" but can be broadly considered to translate as clotting outside of the body in this case.

So what happens during clotting within the body and what happened in joko's tumbler?

When a wound occurs, the first thing that happens is that circulating platelets race to the site and attach themselves to the site of injury. Thanks to a plasma protein called Von Willebrands Factor and other proteins, the platelets effectively form a plug. Now this entire mechanism is called primary homeostasis.

Secondary homeostatis then seamlessly follows because a clot made by platelets is not strong enough to withstand the pressure of blood behind it. In a wound near a major artery, any such plug would be next to useless. So what happens is that other plasma proteins move in to strengthen the platelet plug. These proteins are called Factors and are very complex molecules, so complex that they are referred to as "Factor" followed by a set of roman numerals. Fibrin strands are thus created and these form a mesh around the platelet plug, strengthening it. The entire mechanism is called a "coagulation cascade".

So now that I've bored you with the mechanism, let's look at what happens in joko's tumbler. The steps in the coagulation cascade continue to occur outside the body, in this case the glass and the fibrin will continue to form from the surface of the blood down.

The proteins involved in the mechanism came out of joko's nose with the blood. The blood will continue to clot from the top down but some liquid blood may remain in the tumbler. You can regard it as the fibrin formation mechanism running out of steam but I don't want to go into why it happens this way as I've tried to keep all this as simple as possible - clotting in reality is a really complex process that even at uni level takes a few lectures to get your head around.

In vitro clotting time in a case like this is likely to be between 4 and 8 minutes but it can be affected by some foodstuffs, vitamin k level, hrt and other hormone therapy, liver disease etc amongst others plus the usual culprits such as anticoagulation therapy. The cleanliness of the container can also play a part as can the surface area exposed to the atmosphere.

The account above is far from the whole story of how blood clotting works but it should give readers some idea.

[Sqad]

Excellent reply prof and I have only one change to make...a simple but important one.

/////the first thing that happens is that circulating platelets race to the site and attach themselves to///

The first thing that happens in a wound is that the capillaries retract thus reducing the bleeding before blood clots.


I find it difficult on a website to judge the level at which to pitch the answer.

[theprof]

You're absolutely right Sqad and I'm grateful for the reminder. Thank you. That important vasoconstriction aspect was forgotten in my account.

I know exactly what you mean about pitching an answer and for me, I spent a while thinking about how to answer this question. I went back to think of the terms AB readers might have heard of and tried to confine myself to them. More complex discussions about such things as pathways, peptides and dimers had no place here although I thought Von Willebrand might be worth a mention.

It's been a few years since I lectured on this subject to medical undergraduates.

[Sqad]

Your input is always welcomed and valued.

[Mexican18]

Isn't losing a quarter of a pint of blood from your nose a bit worrying?

[Sqad]

Mexican.......yes,if it doesn't stop,but not really if it is controlled.

[joko]

Thanks theprof :)

[joko]

mexican - yes, i had to have it cauterised in the end - they said it was a 'varicose vein' in my nose, it just kept bleeding whenever it felt like it.

[poppy16]

you must have a good fibrinogen rate, be glad