Flashcards in Pathoma- 1a hemostasis and bleeding disorders Deck (74)
What is hemostasis?
repairing damaged blood vessels
What is a thrombus?
What is the 1st stage of clot formation?
What is the goal of 1a hemostasis?
formation of a weak platelet plug
What is the goal of 2a hemostasis?
stabilization of platelet plug
2a hemostasis is mediated by the _____.
What is the first step of 1a hemostasis?
rapid, transient vaso-constriction of the damaged BV ("knee-jerk reaction")
____ and ____ modulate the first step of 1a hemostasis.
Neurostimulation and endothelien (from the endothelial cells)
What is the 2nd step of 1a hemostasis?
Von Willebrand factor lines the damaged area by binding to exposed collagen
Why does Von Willebrand factor bind to the damaged vessel?
to allow platelets to bind to them via GPIb receptor
Platelets bind to Von Willebrand factor via ____.
Where does Von Willebrand factor come from?
2. endothelial cells (in the Weible-Palae body)
What do Wible-Pilate bodies contain?
P-selectin and Von Willebrand factor
What is the 3rd step of 1a hemostasis?
activation of platelets
What are the 2 mediators platelets secrete to activate themselves?
Thromboxane-A2 is a derivative of ____.
What kind of granule carries ADP?
ADP induces the platelets to express the ____ receptor.
What does GPIIb/IIIa do?
allows the platelets to aggregate to one another
Thromboxane-A2 (TXA2) does what?
signals additional platelets to aggregate
What is aggregation?
when all the platelets join together at a particular place where initial platelets have adhered
What is adhesion?
platelets binding to subendothelial collagen via Von Willebrand factor
What is the molecule that links platelets to each other?
Adhesion causes a ____ in platelets and _____, which releases multiple mediators.
shape change; degranulation
Platelets aggregate at site of injury via ____ using ____ as a linking molecule.
What is the result of 1a hemostasis?
formation of a platelet plug
Name the 2 types of general disorders of 1a hemostasis.
1a disorders of hemostasis are usually due to _____.
abnormalities in platelets
When pts have 1a hemostasis platelet disorders, they will classically present with ____ and ____ bleeding.