Heme Flashcards
check serum levels of what (2) for B12 deficiency
inc homocystein & methylmalonic acid
where is vit b12 (cobalamin) stored
liver
increased demand of folate/b12
preg, cancer, hemolytic anemia, infancy
increased loss in folate def (2)
dialysis, skin disorders
what’s only seen in b12 def (vs folate def)
numbness/tingling/abnormal neurologic exam
methylmalonic acid builds up in myelin
which anemia doesn’t show hepatosplenomegaly
iron deficiency anemia
jaundice: what’s going on w/ RBCs?
hemolysis
s/s of acute vs chronic hemolysis
pallor, fatigue, jaundice
acute: fever, chills, headache
chronic: hepatosplenomegaly, gallstones
schistocytes
non-immune hemolytic anemia
def: fragmented cells
mechanical stress
- intravascular: fibrin
- extravascular: prosthetic valves
what receptor on the plt does vWF binds to
GP1b
vWF is derived from (2)
- plt: a-granules
2. endothelial cells: Wiebel-Palade bodies
4 steps of Primary Homeostatis
- transient vasoconstriction (reflexive neural stimulation, endothelin from endo cells)
- plt adhesion to surface of disrupted vessel’s (plt’s GP1b-vWF)
- plt degranulation (ADP-> expose GP2b/3a, TXA2)
- plt aggregation (btw plt’s GP2b/3a–fibrinogen linker molecule)
site of production: EPO vs TPO (thrombopoietin)
EPO: renal
TPO: liver
activation of cag cascade requires (3)
- exposure to activating substance
- extrinsic: tissue thromboplastin -(activates)-> factor 7
- intrinsic: subendothelial collagen -> factor 12 - phospholipid surface of plt
- Ca2+ (from plt dense granules, ADP is also in there )
defects in thrombin generation -> bleeding: except for which factor
Factor 12 defect: no effect in bleeding
Desmopressin
releases vWF from endothelial cells (but not from plts)
vWF stabilizes/increases half-life/prevent degradation of which factor?
factor 8
condition associated w/ low vWF
hypothyroidism, type O blood type
acquired risk factors of DVT
antiphospholipid antibodies, etc.
genetic risk factors of DVT
Thrombin inhibitors (Protein C/S, antithrombin), F5 Leiden, Prothrombin gene mutation, elevated F8?
Factor V/5 Leiden
single mutation in F5 -> dysfunctional F5 -> “activated protein C resistance”
lab test: “Activated protein C resistance” assay, or genetic test
What factors do Vitamin K activate?
Factors 2, 7, 9, 10, Protein C, S
What enzyme does Vit K inhibit? what process is that enzyme involved in?
epoxide reductase in the liver activates Vit K
things that can prolong PT (4)
- warfarin use
- DIC
- liver failure
- factor 5 or 10 deficiency
