Blood Stuff 1.1

Question 1

Hemostase vs Coagulation

p3

Answer 1

Coagulation is one of the steps of hemostasis

Hemostasis involves all the parts (5 steps) involved in the clot formation

p3

Question 2

Phase vasculaire

Answer 2

vasoconstriction of the vaisseaux as a response to a breach

This is just to reduce the overal flow of blood into the damaged site

Question 3

THROMBOPOÏÉTINE

What it is and production

Answer 3

Synthesized in the liver

The liver produces a constant rate of thrombopoietine

If there are a lot of plaquettes in the blood, they will bind to trhombopoetine -> less thrombopoetine gets to the moelle osseuse -> less plaquettes are synthesized and vice versa

a mechanism of regulation

Question 4

Facteur von Willebrand

Answer 4

Protein that travels in blood and binds on damaged blood vessels

Specifically binds to exposed collagen

When bound, plaquettes can recognize it (FVW) and bind to it to form a blood clot (coagulate)
This step is called addhesion via
Ib-V-IX receptors

When bound, the plaquettes send signals and express Receptor IIb-IIIa

This step in important for aggregation

ATTENTION!!
Récepteur Ib-V-IX
- responsable de l’adhésion
- médiateur : fVW
Récepteur IIb/IIIa
- responsable de l’aggrégation
- médiateur : fibrinogène

Question 5

Recepteurs Ib-V-IX vs IIb-IIIa

Answer 5

Ib-V-IX receptor is important for initial adhesion where as IIb-IIIa is important for aggrgation

1b-5-9 are the facteur van willbran sensors!

Question 6

The most important product of coagulation?

Answer 6

Fibrin
THE GLUE

It is the goal of coagulation which solidifies the platelets!!!

Question 7

Why are thre so many facteurs de coagulation

Answer 7

Because coagulation is a dangerous process that needs to be well controlled

Question 8

Given the cascade of coagulation, what is the ultimate goal?

Answer 8

The transformation of Fibrinogen into Fibrin

Question 9

La voie commune de la cascade and the involved facterus

Answer 9

10(X) + 5(V) -> 2(thrombin’IIa) -> 1(fibrin; Ia)

Question 10

Role of thrombin

Answer 10

It is the facteur that allows to go from Fibrinogen -> Fibrin

Question 11

Temps de prothrombine

Answer 11

Addition of Facteur tissulaire (FT) + Calcium -> activation of extrintic route -> fibrinogene and then fibrin

We can measure the time to get fibrin or the clump as the time for coagulation

PT = play tenis = outside= exogene route

Question 12

Temps de céphaline active - TCa

Partial thromboplastin time

Answer 12

Similar to the temps de prothrombine, this route tests the speed of the intrinsic route

requires phospholipds

Partial thromboplastin time -> Play Table Tenis -> inside -> intrinec

Question 13

Role of calcium

Answer 13

Coagulation cannot occur in the absence of Calcium

Question 14

Where do plaquettes come from?

Answer 14

megakaryocytes

Question 15

True or False,
Plaquettes are the most important and strongest response to stop bleeding

Answer 15

False,

Platelets is liek the first step. You need coagulation!!

Question 16

Thrombin role in the coagulation cascade?

Answer 16

Activation du fibrinogène
* Activation du fXIII
* Activation rétrograde des
facteurs V, VIII, XI (like a bomb reaction; more more more; amplification)

Question 17

What is the most important factor to initiate the coagulation cascade? ?

Answer 17

Facteur tisulaire

Question 18

Can you study facteurs de coagulation in serum?

Answer 18

NOPE

Serum = no anticoagulant

Ne contient pas les facteurs
de coagulation (car
consommés dans le caillot)

Question 19

You are doign a prothombin time and céphaline active time. You notice that both of them work well but the patient still has coagulation problems. WHy?

Answer 19

The patient likely has an issue in the voie commune and his intrinsic and extrinsic pathways work well

Question 20

What is Rapport international normalisé (RIN)?

Answer 20

Key to normalize values across laboratories in the efficency of warfarine

Temps de prothrobmotin standartize following a prescription

Question 21

Retraction du caillot

Answer 21

Step 4 of coagulation

This is a step that involves the post activation of the plaquettes by thrombin.

This makes the plaquettes explode and have projections that will grab both ends of the damaged vaisseau and try to bring them together to close the hole.

Question 22

The most important player in the destruction of the caillot?

Answer 22

Plasmin

It can break fibrin bonds (fibrinolyse) and leads to the breakage of the clot after the closure of the vessel

Question 23

Role of facteur XIII

Answer 23

Glue fibrins together

Question 24

Caillot rouge vs caillot blanc

53 minutes

Answer 24

Caillot Rouge
Globules rouges
« coincés » dans un
treillis de fibrine
Caractéristique des
thromboses veineuses

Caillot Blanc: Thrombose arterielles

Question 25

Antithrombine and what amplifies it

Answer 25

Prevents the activation of thrombine

fortement amplifiée par l’heparan sulfate (héparine)

Question 26

Complexe protéine C activée et protéine S

Answer 26

BLockers of coagulation

Clivage enzymatique des facteurs Va/VIIIa

Protéine C activée détruit
les facteurs de coagulation
là ou ils ne sont plus utiles

Question 27

thrombomoduline

Answer 27

Factor that is found on healthy endothelium and that binds thrombonin preventing its activity

This blocked thrombonin has now an effect of activatin protein C, which as we know:

Protéine C activée détruit
les facteurs de coagulation

Question 28

Heparin

Answer 28

Medication that blocks coagulation

Antithrombine est fortement amplifiée par l’heparan sulfate (héparine)

Augmente l’effet inhibiteur de
l’antithrombine

Question 29

La faoi est l’endroit de synthèse de presque tous les
facteurs de la coagulation
! Exception and what is the problem?

Answer 29

VIII et von Willebrand

IF a ptn has a cirrose du foie they will have lowered coagulation factors but not von Willebrand or VIII

Question 30

Hemophilie A vs B

Answer 30

Déficit en facteur VIII (hémophilie A) : 80%
! Déficit en** facteur IX **(hémophilie B) : 15%

Question 31

Hemophilie Transmission

EXAM EXAM EXAM

Answer 31

Transmission is done via chromosome X

A boy has an X and a Y chromosome

A girl has two X chromosomes

Must understand that this affects mainly guys. The reason is that both chromosome X must be affected in a girl for her to be sick. Whereas a guy only has one chromosome so, just getting one X is sufficient.

If a father is touched by hemophilie, it’s son will never never have hemophilie because the affected chromosome X is not transmitted. Intead, the boys take the healthy chromosome X from the mother

However, the daughters will 100% carry hemophilie because they must take one X chromosome from father and one from mother. Again here, they carry the mutation but it is recessive i,e not showing.

On the other hand, if the mother is affected, well there is a 50% chance of transmitting the affected X chromosome to ether a guy or a girl so 50 50 chance for both guy and girl to hav ethe mutation.

But here again, the girl that takes the mutated chromosome X will only carry and not show since the other chromosome comes from the father

On the other hand, the affected boys will display hemophilie because they only have one X

Question 32

Maladie de von Willebrand

Answer 32

In contrast to hemophilie, this is autosomale dominante

This means, having one bad chromosome is sufficent to produce symptoms and so it affects girls and boys

Question 33

Anti-vitamine K and effect

Answer 33

This is a medication by the name of Coumadin

It blocks vitamin K activity

Vitamin K is key for facteurs II, VII, IX et X

which are essential across the coagulation path

i.e, blocks coagulation