What is the major regulatory enzyme for Thrombopoiesis?
Where does Thombopoietin come from?
Continually produced by the liver, bone marrow, endothelium ect.
______ stimulates megakaryocyte production and differentiation
Thrombopoietin binds to _____ in ciruclation
When _____ numbers decrease there isn't enough in ciruclation to pick up the thrombopoeitin, leading to increased thrombopoietin free in plasma that ciruclates to the bone marrow and stimulates production of _____
Platelets are part of _____ hemostasis
_____ Provides a surface for which secondary hemostasis occurs on
How long does it take to form the primary hemostatic plug?
In the formation of the primary hemostatic plug, platelets adhere to exposed ______
Once platelets adhere to subendothelium they undergo ____, leading to a shape change
After platelets are activated, they begin to secrete _____
After platelets have activated and secreted granules, they _____ to form a platelet plug
For platelets to adhere to the subendothelium they require ______Factor
Von Willebrand factor
Von Willebrand factor binds to ____ on the platelet surface and forms a bridge between the platelets and subendothelium
During primary hemostasis, when platelets ____ , they start to undergo shape changes where they grow long extensions and increase their surface area by 3-5%
*Increase their surface area
The majority of negatively charged phospholipids are kept on the inside of the platelet, but when the platelet becomes activated they _____ their membrane in order to carry the negative charge on the outside
After platelets become activated, what two things are secreted in their granules?
Von Willibrand factor
*Von willebrand factor calls more platelets to the site
During activation platelets secrete _____ which comes and coats the top of the negatively charged platelets, so the platelets become positively charged
Calcium is secreted in platelet granules that coat the platelet with a positive charge which is important for creating the surface for the _____ factors to come down and bind to form fibrin
Once the granules are stimulated to form platelet aggregation, _____ binds to the platelets and starts bridging the adjacent platelets.
When _____ binds to activated platelets and bridges adjacent platelets is when you get formation of the platelet plug
True/False: Platelet aggregation is a reversible process
Platelets provide a surface for formation and deposition of ____
Platelets activate their cytoskeleton to _____ the clot in order to facilitate wound closure and vessel patency
What laboratory tests are used to assess platelet concentration?
Spontaneous hemorrhage occurs when platelet numbers decrease below ______
What laboratory tests do we use to access platelet morphology?
Increased MPV suggests increased ______
What does the presence of macrothromobocytes suggest?
Increased platelet production
What are the tests used in the clinical setting to evaluate platelet function?
*Buccal mucosal bleeding time or cuticle (toenail) bleeding time