Easy Coagulation Cascade (1 of 2) - Simple & easy to remember

My name's Andrew. I'm a medical student and a little while ago I was trying to figure out the
...
coagulation cascade. I hate it.
You probably hate it too
and I realized I had never seen a picture of the coagulation cascade that made any
sense to me or that I thought i could remember at all.
So I kind of came up with my own way to remember it and i hope it helps you as well.
I'm just going to start by doing the
intrinsic
pathway. It's the pathway with the most steps (it has the most factors in it)
and I'll just kind of branch everything else off from that. Just so you know,
I don't do the steps where it shows
12 being converted to 12a
I just draw an arrow from what is catalysing the reaction straight to what the
product of that is. That helps me keep
all the clutter off.
I'm going to start with
collagen or activated platelets (that's the way I learned it). So
either one of those can activate
this pathway. We'll put an 'a' for 'activated'.
Either of those
can activate
factor 12 to 12a.
That is the first step,
and I'm just going to keep going with these. 12a
catalyses
11 to 11a.
11a catalyses the step to 9a.
9a
catalyses the step to 10a.
10a
catalyses the step
to...
I use just the numbers,
you might now it as 'prothrombin' into 'thrombin'; I just use 2 to
2a. So this, 2a,
you will probably see that in your charts as
'Thrombin'.
And then thrombin (2a) activates fibrinogen
to fibrin. Fibrin is '1a'.
And finally 1a
eventually will turn into
stable
(stabilized) fibrin.
Okay. And you I know you know that that's
way too simplified so lets add in some of the details.
First I'll just add in
my little
arrows
so we can keep straight where we are going.
...
You know that a couple of these steps require more than just one thing. Often you require two
factors.
So what I do is, I just add in those "buddy factors" as I think of them
just here on the right side. So
8a
is the factor that helps 9a
to convert 10 to 10a.
So then I'll just write in
8a.
You know that 8a comes from 8.
10a in order to convert
prothrombin to thrombin
requires
5a
(which of course comes from 5 -
it's not rocket science) and then
1a, in order to become stabilized,
requires the help of
factor 13a.
So hopefully at least, for you and i know for me, this is
a lot simpler than what I've seen.
And this takes care of
wellÉ a lot of it. I guess we still a few more details to add in.
So 8a
5a and 3a,
in order to be activated, they all require the help of THROMBIN which
is 2a. So I'm just going to drawÉ these arrows indicate that that's
what's helping this form. I'm going to draw arrows over here to show that 2a
is helping form
all of these.
2a,
5a
and 13a. So those ones all require
thrombin in order to be formed.
Another thing that you probably need to know is the ones that
require calcium.
How I do this is I remember the ones that need calcium to be activated.
The product...
to get that product that
you need calcium. And I give these ones a double circle. It's just how I think about it.
So 9a
requires calcium
to be formed from 9.
The same is true
for 10
and 2.

And that...
you know, i think that's pretty much, for basic starting point, just trying to figure
things out... it's pretty much the
Intrinsic pathway of coagulation.
So the only thing to add now is the extrinsic pathway.
The extrinsic pathway
comes in and matches up into 10a. There is a different way to make 10a besides
using 9a you can use 7a.
And that i just go over here... 7a
In order to make 7a you also need calcium
so I'm going to give that the same
double circle.
And give it a little arrow here.
The one last thing just is what activates that. Thromboplastin
you've probably heardÉ "thrombo-"
I'm going to split it into 2 lines. It's one word.
Thromboplastin. And I forgot one step
as far as we've been
giving these guys circles because they require calcium
In order to get stabilized fibrin from 1a you need to use calcium there.
So I'm going to give this
a box as well.

There you have it. A pretty easy way to remember.
Another interesting factoid (another reason I like this) is the way it is set up here
all of the ones with the double circle
not including this (stabilized fibrin)
just the 7,
9, 10 and 2,
these guys are all...
(you might recognize them)
they all require vitamin K
in order to be produced in the liver -
to produce that inactive form.
So 7 seven in order to be produced in the liver would require vitamin K.
And that is pretty much it. If you have any questions or if you notice that
I did something wrong or misspoke, just let me on the comments and I will do my
best to come up with a better video for you next time. Thanks! Bye.