hemostasis Flashcards
hemostasis
bodys ability to maintain integrity of blood and blood vessels
how does body maintain hemostasis
interaction between vessels, platelets, and coag factors
primary hemostasis
vascular response (vessels contract due to injury) and platelet response (become sticky using von Willebrand’s) platelet plug
secondary hemostasis
coag cascade (made in liver, forms fibrin clot)
fibrinolysis
dissolves clot, activation of plasminogen into plasmin
primary hemostasis is the
interaction between platelets and vessel wall
circulating blood contacts the
subendothelial (connective tissue)
vascular spasm
immediate but temporary closure of blood vessel by contraction stimulated by nervous system response
platelet plug formation
stimulated by vWF
adhesion of platelets
platelets stick to connective tissue
aggregation of platelets
forms plug, thromboxane stimulates platelets to join, only in small vessels
secretion of platelets
vasoconstriction and further aggregation
acquired primary hemostasis disease
vasculitis, collagen deficiency, extensive vascular injury
inherited primary hemostasis disease
von Williebrands
most common cause of bleeding disorders
thrombocytopenia
von Willibrands disease
lack of vWF (dobies)
clinical signs of vWD
spontaneous hemorrhage from nose, vagina, urinary bladder, mucous membranes, prolonged bleeding time
treatment of vWF
transfusion of dog blood products, suture bandage or wound glue, should not be given drugs
dogs having low plasma below 50%…
may be as risk of expressing vWF
dogs having low plasma below 25%…
severely affected by vWF
secondary hemostasis requires
coagulation (clotting) factors
cascade
conversion of inactive factors to active factors (domino effects)
fibrin clot is….
long lasting (minutes to hours)
coag factor substances are made in the
liver
