Haemostatis & Thrombosis Flashcards
Which cells have Integrin alpha 2b beta 3?
Exclusively platelets
What does Integrin alpha 2b beta 3 bind to?
VWF (von Willebrand Factor) and fibrinogen
What does Integrin alpha 2 beta 1 bind to?
Collagen
What does GP VI bind to, and which cells is it found in?
Collagen, and exclusively platelets
Which cell type is the GPIV-IX-V receptor found in?
Exclusively platelets
Where cells are the subunits to integrin alpha 2b beta 3 (subunits being alpha 2b and beta 3) present on?
Beta 3 subunit is also found on epithelium (on epithelium it binds to the alpha V subunit instead)
Alpha 2b subunit is only found on platelets
What is thrombosis?
Too many platelets, forming blood clots
What is haemostasis?
The process of stopping bleeding
Where do platelets originate, as a part of what cycle?
In bone marrow, as part of the haemopoesis cycle
What stimulates megakaryocytes?
Thrombopoietin (TPO), cytokines and growth factors
What is the maturation of megakaryocytes called?
Endomytosis
What cells are platelets derived from? What is the progression of cell differentiation to form platelets?
Stem cells form myloid cells (CMP), which form megakaryocytes, which form platelets
Which receptors initiate adhesion on platelets?
GPIb-IX-V and GPVI
Which receptors initiate activation of platelets?
GPIb-IX-V and GPVI
What does GPIb-IX-V bind to?
Mainly VWF, also Leukocyte integrin alpha M beta 2, P-selectin, Thrombin, Factor XI, and Factor XII
What is in alpha granules?
Fibrinogen and VWF
What is the role of the cytoskeleton in blood clotting?
Controls activation of integrin by conformationally changing platelets
What is shear and why is it important
The stress exerted by the wall on the fluid by changing diameter. High shear activates platelets
Tool to produce artificial shear conditions
Cone plate discometer
How COVID-19 vaccine is related to blood clotting
Platelet 4 binds to heparin. These both bind to antibody to activate platelet. Antibody generated after COVID vaccination.
