Platelets & Clotting
how long do these spasm last?
30 seconds
How long do they live?
9-12 days
What are platelets?
Cell fragments
what phase starts 30 seconds after this?
Coagulation phase
what is the function of platelets?
Initiate clotting process and help close injured blood vessels
what happens when the wall of the vessel is cut?
It triggers a contraction in the smooth muscles that decrease muscle size
as more platelets arrive, what do they form?
Platelet plug
what phase begins when platelets attach to the sticky endothelial cells & exposes collagen fibers within injury?
The platelet phase
what happens to the endothelial cells?
They become sticky
What is the scientific name for platelets?
Thrombocytes
what do we call an abnormally low platelet count?
Thrombocytopenia
what is hemophilia?
a rare, inherited bleeding disordr in which your blood cells don't clot normally
what are the clotting factors?
calcium ions & 2 different plasma proteins
these pathways join at the...
common pathway (achvanon of the factor x)
what is the smooth muscle & inner lining of the walls of blood vessels called?
endothelium
What is the scientific name for clotting?
hemostasis
where does the intrinsic pathway begin?
inside the bloodstream
Where/how do platelets form?
megakaryocytis- continuously shed cytoplasm in small closed packets
where does the extrinsic pathway begin?
outside the bloodstream in the vessel wall
what phase is this?
vascular
what is a blood clot?
when blood cells & additional platelets are trapped within the fibrous tangle
hemophilia A is...
you have little to no clotting (factor VII)
hemophilia B is...
you're missing of have low levels of clotting (factor IX)
