RED BLOOD CELL AND BLEEDING DISORDERS I Flashcards
(41 cards)
effects of ____ are mainly due to the loss of intravascular volume , which if massive can lead to cardiovascular collapse, shock, and death
acute blood loss
_________ induces anemia only when the rate of loss exceeds the regenerative capacity of the marrow or when iron reserves are depleted and iron deficiency anemia appears
chronic blood loss
_______- anemias share the ff features:
1. a shortened red cell life span below the normal 120 days
2. elevated erythropoeten levels and a compensatory 3. increase in erythropoiesis
hemolytic anemias
if persistent extravascular hemolysis leads to a hyperplasia of phagocytes manifested by varying degrees of ________
splenomegaly
_________ is most commonly caused by alterations that make red cells less deformable
extravascular hemolysis
________ hemolysis of red cells may be caused by mechanical injury, complement fixation, intracellular parasites, or exogenous factors
intravascular hemolysis
iron released from hemogloblon can accumulate withink tubular cells giving rise to renal _________
hemosiderosis
_________ is an inherited disorder caused by intrinsic defetc in the red cell membrane skeleton that render cells spheroid, less deformable, and vulnerable to splenic sequestration and destruction
hereditary spherocytosis
in spherocytosis, _____ occurs in 40%-50% of affected adults , moderate _______ is characteristic (5000-1000 g)
cholelithiasis
splenomegaly
hereditary spherocytosis
general stable clinical course is sometimes punctuated by ________, usually triggered by an acute parvovirus infection
aplastic crises
hereditary spherocytosis
_______- are produced by intercurrent events leading to increased splenic destruction of red cells
hemolytic crises
abnormalities in the _________ shut or glutatathione metabolism resulting from deficient or impaired enzyme function to reduce the ability of RBCs to protect themselves against oxidative injuries and lead to hemolysis
hexose monophosphate shunt
G6PD
G6PD is present in about 10% of american blacks, mediterranean is present in middle east
high frequency of these variants in each population is believed to stem from protective effect against __________
plasmodium falciparum
G6PD
exposure of G6PD deficient red cells to high levels of oxidants causes the cross linking of reactive sulfhydryl groups on globin chain which become denatured and form membrane bound precipitates known as _____________
heinz bodies
__________ is a common hereditary hemoglobinopathy caused by a point mutation in beta globin that promots the polymerization of deoxygenated hemoglobin, leading to red cell distortion, hemolytic anemia, microvascular obstruction, and ischemic tissue damage
sickle cell disease
sickle cell disease is a caused by a ______ mutation in the beta globin gene that leads to the replacement of a charged glutamate residue with a hydrophobic ______ residue
missense mutation
valine
high prevalence of sickle cell trait in certain African populations stems from its protective effects against ________
falciparum malaria
sickle cell anemia
in some individuals HbF expression remains relatively high, a condition known as ___________ in these individuals, sickle cell disease is much less severe
hereditary persistence of fetal hemoglobin
Sickle cell anemia
_____________, higher HbS concentrations increase the probabilty that aggregation and polymerization will occur during any given period of deoxygenation
mean cell hemoglobin concentration
sickle cell anemia
a ______ in pH reduces the oxygen affinity of hemoglobin, thereby increasing the fraction of deoxygenated HbS at any given oxygen tension and augmenting the tendency for sickling
intracellular pH
Sickle cell anemia
________- also are present in red cells due to asplenia
howell jolly bodies
sickle cell diseases causes a moderately severe hemolytic anemia (hematocrit 18%-30%) associated with _________, _______, and ________-
reticulocytosis
hyperbillirubinemia
presence of irreversibly sickle cells
clinical features of sickle cell disease
_______ also called pain crises are episodes of hypoxic injury and infarction that causes severe pain in the affected region
these frequently manifest as the ______ or dactylitis of the bones of the hands and feet,
_________– is a particularly dangerous type of vaso-occlusive crisis involving the lungs that typically presents with fever, cough, chest pain, and pulmonary infiltrates
vaso-occlusive crises
hand foot syndrome
acute chest syndrome
Sickle cell anemia
__________- stem from the infection of red cell progenitors by parvovirus
aplastic crises