Arterial and Venous Thrombosis

Question 1

Hemostasis and thrombosis primarily involve the interplay among 3 factors

Answer 1

1. Vessel wall
2. Coagulation and fibrinolytic proteins
3. Platelets

Question 2

Difference of arterial and venous thrombosis.

Answer 2

In venous thrombosis, primary hypercoagulable states reflecting defects in the proteins governing coagulation and/or fibrinolysis or secondary hypercoagulable states involving abnormalities of blood vessels and blood flow or stasis lead to thrombosis.

By contrast, arterial thrombosis is highly dependent on the state of the vessel wall, the platelet, and factors related to blood flow.

In the setting of stasis or states of hypercoagulability, venous thrombosis is activated with the initiation of the coagulation cascade primarily due to exposure of tissue factor; this leads to the formation of thrombin and the subsequent conversion of fibrinogen to fibrin. In the artery, thrombin formation also occurs, but thrombosis is primarily promoted by the adhesion of platelets to an injured vessel and stimulated b ex osed extracellular matrix.

Question 3

Platelets.

Answer 3

Disc-shaped, very small anucleate cells 1-5 um in diameter that circulate in the blood at concentrations of 200-400/ul, with average life span of 7-10 days.

Question 4

What are the 2 major types of platelet granules?

Answer 4

1. Alpha-granules - Contain soluble coagulation proteins, adhesion molecules, growth factors, integrins, cytokines, and inflammatory modulators. Platelet dense-granules are smaller than alpha-granules and less abundant.
2. Dense granules - contain high concentrations of small molecules, including adenosine diphosphate (ADP) and serotonin that influence platelet aggregation and other related vascular processes, such as vasomotor tone.

Question 5

This bind to the exposed von Willebrand factor, causing platelets to adhere.

Answer 5

GPIb-IX-V complex

Question 6

It is a trimeric transmembrane protein of the tumor necrosis factor family and with its receptor, is an important contributor to the inflammatory process leading to thrombosis and atherosclerosis,

Answer 6

CD40 ligand

Question 7

Cancer patients have ___fold increased risk of VTE as compared with the general population, and cancer patients have ___ survival.

Answer 7

Fourfold; reduced survival.

Question 8

It has been reported that the risk of VTE doubles after air travel lasting ___ hours.

Answer 8

Four hours

Question 9

Mechanisms involved in altered fibrinolytic activity in metabolic syndrome.

Answer 9

Altered platelet function; procoagulant and hypofibrinolytic state; increased plasma levels of plasminogen activator inhibitor type 1 (PAI-1)