Coagulation Cascade

Question 1

What are the antithrombotic properties of the intact endothelial vessel wall?

Answer 1

• Negativity charged heparin like glucosamino glycans.
  *Neutral phospholipids
• Platelet and coagulation factor inhibitors
• Fibrinolysis activators

Question 2

What are the Thrombogenic factors of subendothelium ?

Answer 2

*Subendothelial collagen
*VWF
* Laminin, thrombospondin, and vitronectin ( involved in platelet adhesion)

Question 3

What is the acute effect of vascular insult?

Answer 3

Acute vascular insult causes neurogenic reflex vasospasms and local release of endothelin and platelet derived Thromboxane A2.

Question 4

What are the circulating Thrombogenic factors?

Answer 4

Platelets
Platelet activating factors
Clotting factors
Prothrombin
Fibrinogen
vWF

Question 5

What are the circulating antithrombigenic factors?

Answer 5

TPA
Antithrombin
Protein C and S
Plasminogen

Question 6

What are the contents of alpha granules of platelet?

Answer 6

• P-selectin
  *Fibrinogen and fibronectin
  *Factor V and VIII
• Platelet factor IV
• Platelet derived growth factor
• TGF-Alpha

Question 7

What are the contents of delta or dense granules of platelets?

Answer 7

• ATP, ADP, calcium
• Serotonin
• Histamine
• Epinephrine

Question 8

What are the steps of primary hemostasis ?

Answer 8

• Platelet adhesion
• Platelet secretion/ degranulation
• Platelet aggregation

Question 9

What happen during platelet adhesion ?

Answer 9

The vWF acts as a bride between endothelial collagen and platelet surface receptor GP1b promotes platelet adhesion.

Question 10

What happen during platelet degranulation?

Answer 10

It is marked by degranulation of alpha and dense granules by secreting calcium and other substances. Calcium binds to the circulating phospholipids ( secondary to platelet activation) and provide binding sites for coagulation factors.

Question 11

What happen during platelet aggregation?

Answer 11

Thromboxane A2 and ADP promotes platelet aggregation by crosslinking platelets via GP2b3a.

Question 12

What is the mechanism of localized primary plug formation?

Answer 12

The fine balance between the Thrombogenic factor Thromboxane A2 and antithrombigenic factor Prostacycline prevents the extension of the clot.

Question 13

Deficiency of Glycoprotein IIb/IIIa cause?

Answer 13

Glanzmann thrombathenia

Question 14

Deficiency of Glycoprotein Ib cause?

Answer 14

Bernard Soulier syndrome