Chapter 142 - Arterial and Venous Thrombosis Flashcards
Which of the following was estimated as more common in 2009 in the United States - coronary artery non-silent new events or new or recorrent cerebral stroke?
Stroke.
“In 2009 in the United States, an estimated 785 000 people had a new coronary thrombotic event (…) approximately 795 000 people had a new or recurrent stroke.”
Name the differences in arterial and venous thrombosis.
“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.”
Give examples of platetet functions that are not related to its primary function of regulation of hemostasis.
“In addition (…) our understanding of their role in other processes, such as immunity, wound healing, and inflammation, continues to grow.”
What is the estimation death rate for coronary artery disease and stroke in the United States?
Coronary artery disease - “about 1 of every 5 deaths”
Stroke - “it is estimated that 1 of every 18 deaths”
What is the normal lifespan of a healthy platelet?
7 to 10 days.
What are the differences between alpha and dense granules of the platelets?
“The two major types of platelet granules, alpha and dense, are distinguished by their size, abundance, and content. 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. Whereas alpha-granules contain proteins that may be more important in the inflammatory response, dense-granules contain high concentration of small molecules, including adenosine diphosphate (ADP) and serotonin, that influence platelet aggregation.”
Which subendothelial molecules might be responsible for the adhesion of platetelet to the vessel wall?
“Damage exposes subendothelial components responsible for triggering platelet reactivity, including collagen, von Willebrand factor, fibronectin, and other adhesive proteins, such as vitronectin and thrombospondin.”
Collagen-induced platelet adhesion is dependent on the platelet receptor glycoprotein (GP) IV, GPVI and integrin alpha2-beta1.
True or False?
True.
<p>Which platelet receptors are involved in the adhesion to von Willebrand factor?</p>
<p>GPIb-IX-V</p>
What is the platelet ligand for fibrinogen? How come platelets in innactive state do not ligate to fibrinogen?
GPIIb/IIIa.
“von Willebrand factor-bound GPIb-IX-V promotes a calcium-dependent conformational change in the GPIIb/IIIa receptor, transforming it from an inactive low-affinity state to an active high-affinity receptor for fibrinogen.”
This conformational change might be mediated by many other receptor-ligand complexes.
The platelet membrane is both enriched with thrombotic and nonthrombotic receptors.
True or False?
True.
Which platelet receptors are the most abundant?
Thrombin receptors.
What is the main function of PAR1 Receptor?
PAR1 is responsible for the cleavage of the N-terminus of thrombin which, in turn, serves as a ligand to this platelet receptor. It is the main receptor for thrombin.
Name the main receptors responsible for platelet aggregability dependent on ADP.
P2Y12 and P2Y1 are the most important ones.
the other receptor for ADP is P2X1
PSGL1, present in platelets, serves as a ligand to P-selectin (CD62P) presente in leukocytes.
True or False?
False.
“Platelets bind via P-selectin (CD62P) expressed on the surface of activated platelets to the leukocyte receptor, P-selectin glycoprotein ligand 1 (PSGL-1).”
