Intro to Hematology Flashcards
what is anemia?
decrease in the circulating red cell mass
what can anemia cause?
tissue hypoxia
Etiology of Anemia
blood loss, accelerated rbc destruction, decreased rbc production
Anemia: Morphology of RBCs
rbc size and MCV (measured corpuscular volume)
RBC count
rbsc per unit volume of blood
hemoglobin measured
hgb per volume of blood
Mean Cell Hemoglobin Concentration
hemaocrit
packed rbc volume
spun
Rericulocyte count
% immature RBcs in peripheral blood
normal reticulocyte %
.5 - 2.5%
what causes acute blood loss/
trauma
Site of RBC production
Embryo:
Fetus:
Kid:
Yolk Sac
Liver
Bone Marrow
Regulation of RBC production
tissue hypoxia induced the production of erythropoetin by kidney
Chronic Blood Loss
slight reticulocye develops
* no anemia
Most common nutrutiional defiency worldwide
iron deficiency
what is iron defiency
defect in hb production (hypochromic) rbcs
‘what causes iron defiency
chronic blood loss
how does iron get absorbed into marrow?
bound to plasma transferin and incorporated into hemoglobin
lab test for iron defiency
blood smear, serum iron, serum ferritin, serum transferrin)
Accelerated RBC Destruction
inheritired/intrinsic (enzyme disorder)
Extreinsic (antibody)
signs of increased RBC production
reticulocytosis
Erythroid hyperplasia of marrow
signs of increased rbc destruction
^ LDH
^ serum unconjugated bilrubin
^increased fecal urobilnogen
decreased haptoglobin
hemolysis
* intrinsic
hemoglobin disorder, membrane defect
enzyme defiencies
inherited
hemolysis
* extrinisic
immune hemolysis
traumatic hemolysis
parasitic hemolysis
acquired
what predominates in most forms of hemolytic anemia
extravascular hemolysis
final common pathway of extravascular hemolysis
decreased RBA deformability
inheritred enzyme disorder (hemolytis)
g6pd deficiency
G6pd deficiency
x-linked recessive (males)
rbc vulnerable to oxidative stress
hemoglobin disorders
structurally abnormal hgb (sickle cell) strucutrally normal (thalassemia)
structure of hemoglobin
tetramer of 4 globin chains
structural variants (disorder hemoglobin)
single amino acid substituion in chain)
hemolysis due to imbalance in globin chain production
Thalassemias
excess globin chains precipitate and damage rbcs
thalassemias
sickle cell disease
point mutation in beta-globin
thalaseemias
imbalance in globin chain production
Traumatic Hemolysis
DIC
disseminated intravascular coagulation
decreased rba production
nutrutional defiencies
causes Megaloblastic anemia
- various drugs
- B 12 defiency
- abnorally large erythroid precursors
Causes of B12 deficiency
impaired absorption (pernicious anemia) inadequte diet
Von Willebrand disease
decreased levels of qualaive defects of vWF
Hemophilla a
F VIII defiency
hemophillia B
F IX deficiency
hemo a and b (linked)?
x linked recessive
acquired bleeding disorder
liver disease, anticoagulant therpay, factor inhibtors, DIC
hereditary bleeding disorder
clotting factor deficiency
vessel wall abnormality
bleeding disorder
decreased platelet #
bleeding disordeer
abnormaility in clotting factor
bleeding disorder
coagulation test
Prothrombin Time
Partial Thromboplastin Time
Prothrombin Time
test for extrinsic and common arms of clotting cascade
PAartial Thromboplastin Time
test for the intrinsic and common pathways of the clotting cascade
normal hemostatic response
blood vessels
plaelets
clotting factors (in plasma)
platelet plug
platelet adhesion
platelet activation
platelet aggregation
firbin plug
requires generation of thrombin via activiation of coagualtion cascade
intravascular cell destruction
results from breach of membrane in ciruclation
extravascular rbc destrcution
ingestion by macrophage (spleen) in response to damaged rbc
what causes hemoglobin to denature and precipitae in cytoplasm as heinz bodies?
g6pd defiency
decrease in marrow mass erythoid rbc precursors
aplastic anemia
