chapter 4 Flashcards
step 1 of primary hemostasis (mediated by)
vasoconstiction
neural reflex, endothelin
step 2 of primary hemostasis
platelet adhesion to VWF via GP1b
step 3 of primary hemostasis
platelet degranulation- ADP and TXA2
action of ADP
exposure of GP11a/IIIb on platelet surface
action of TXA2
promotes aggregation
step 4 of primary hemostasis
platelets aggregate to form plug
2 types of disorders of primary hemostasis
quantitative- decreased # platelets
qualitative- impaired functioning of platelets
clinical findings of TTP/HUS
skin/mucosal bleeding microangiopathic HA (schistocytes) fever renal insuff- HUS CNS abnormalities- TTP
bernard-soulier
GPIb deficiency
galnzmans
GPIIb/IIIa deficiency
parosysmal nocturnal hematuria (cause)
due to defect in PIGA that leads to decreased GP1 on RBC surface = lack of CD55/59 which leaves RBCs susceptible to complement mediated lysis
PHN clinical (4)
hemolytic anemia
pancytopenia
thrombosis
hemoglobinuria
uremia and bleeding
impairs platelet function= leads to d/o of primary hemostasis
complications of hereditary spherocytosis (2)
pigmented gallstones
aplastic crisis in parvo B19 infection
factor V leiden
mutation (glutamine - arginine subs) in factor V makes it resistant to inactivation by activated protein C = increased thrombosis
responsible for converting substances to carcinogens
microsomal monoxygenases (CYP 450)
role of haptoglobin
binds free hemoglobin
when is haptoglobin decreased
hemolysis
acute intermittent porphyria enzyme defect
PBG deaminase
acute intermittent porphyria symptoms
abdominal pain
neuro
port-wine urine
PBG and ALA in urine
causes of pure red cell aplasia (3)
thymoma
lymphocytic leukemia
parvo B19 infection
role of fibronectin
attaches cell integrin to collagen (anchors)
cause of HUS (2)
E coli or shigella infection
HUS symptoms (3)
hemolytic anemia with schistocytes
thrombocytopenia
acute kidney injury
