Anemias Flashcards
what is anemia
reduction of total circulating RBC mass, thus reducing oxygen carrying capacity
what is hemolytic anemia
anemia d/t abnormal breakdown/destruction of RBC
what is macrocytic/microcytic in reference to anemia?
size of RBC in circulation
what is hypochromic in relation to anemia?
pale color compared to bright red of normal RBC
what is extravascular hemolysis?
an alteration that renders RBC less pliable, so it gets trapped in cords of extravascular tissues and macrophaged
what is intravascular hemolysis
RBC lysed intravascularly, releasing plasma into circulation and leaving fragments behind
what is associated with extravascular hemolysis?
membrane abnormalities, immunoglobulins, physical deformities
what is associated with intravascular hemolysis?
physical external trauma or toxic damage
what characteristics do hemolytic anemias share?
- shortened RBC life less than 120 days
- elevated EPO
- compensatory increase in erythropoiesis
- accumulation of hemoglobin degradation products (are created as a result of hemolysis)
what is hereditary spherocytosis?
inherited disorder, RBC become spherelike due to membrane skeleton defects
pathogenesis of spherocytosis?
mutation leading to insufficiency of spectrin, ankyrin, band 3 or band 4.2, mutations introduce frame shifts that are stop codons; spleen traps RBC in cords bc reduced pliability, exacerbates K and water loss (so have increased avg cell Hb concentration due to dehydration by this loss) and are macrophaged
life span of spherocytes?
10-20 days
treatment of spherocytosis
splenectomy
symptoms of spherocytosis
anemia, splenomegaly, jaundice, gallstones, osmotic lysis with introduction of hypotonic salt solutions bc water goes straight to spherocytes and lyses them
what 2 ways do thalassemias cause anemias?
- decreased RBC production
2. decreased RBC lifespan
