Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
|
What an orthochromatic RBC?
|
Precursor RBC with nucleus
|
|
|
How do reticulocytes differ from mature RBCs?
|
Appear bluer (ribosomes) and are larger
But like mature RBCS, they LACK NUCLEI |
|
|
EPO is made in _____.
Which cells are affected by EPO? |
The kidney
EPO increases RBC production/maturation by acting in BFU-E, CFU-E, and Normoblast (erythroblast) |
|
|
Normal Hgb levels.
|
Men: 15 +/-1.7
Women: 13 +/-1.5 |
|
|
Normal RBC counts.
|
~5
|
|
|
Normal hematocrit.
|
Men: 45
Women: 38 |
|
|
EFfect of hydration status on Hgb levels.
|
All measures of anemia measured per plasma volume
Thus, dehydrated pt will have falsely elevated Hgb |
|
|
Effect of pregnancy on Hgb levels.
|
In pregnancy, plasma volume rises disproportionate to RBC volume; so will get falsely low Hgb
|
|
|
Effect of altitude on Hgb levels.
|
High altitude-->inc'd EPO (lower PAO2)
|
|
|
Effect of gender on Hgb levels.
|
Women have lower Hgb than males; likely androgen related
|
|
|
What physical exam findings are general to anemic patients?
What physical exam potential clues may lead to diagnosis? |
Conjunctival pallor
Tachycardia Hypotn Potential clues (less specific): Jaundice (hemolysis) Heart murmur (rbc destruction on damaged valve) Splenomegaly Neurologic (B12 deficiency) |
|
|
Mean Corpuscular Volume:
What is it? Normal value. Abnormal values (categories). |
Avg size of a blood cell
NL: 80-100 If under 80-->microcytic anemia Over 100-->macrocytic anemia |
|
|
Causes of low MCV.
|
Reduced iron availability
Reduced heme synthesis (lead poisoning) Reduced globin synthesis: thalassemia |
|
|
What is thalassemia?
|
Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin, the protein in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia.
|
|
|
Causes of elevated MCV.
|
-B12 and folate deficiency
-Inc'd number reticulocytes (they're bigger than mature RBCs) -Inc'd number target cells (sign of liver dz) -Myelodysplasia |
|
|
Mean Corpuscular Hemoglobin:
What is it? |
Avg amount of Hgb per RBC; tends to parallel MCV
|
|
|
RBC Distribution Width:
What is it? |
Measures variability in size of RBC (anisocytosis) but is NEVER a substitute for examining peripheral smear
|
|
|
What is the normal reticulocyte count?
|
RBCs live 100 days, retics seen only 1 day, thus normal retic count is 1%
|
|
|
These cells exhibit polychromasia.
|
Reticulocytes (blue hue = ribosome)
|
|
|
This test unequivocally identifies reticulocytes.
|
Supravital stain
|
|
|
What is the reticulocyte index and how is it calculated?
|
Retic index adjusts retic count for degree of anemia:
Retic index = retic count x pt hgb/normal hgb |
|
|
What does an elevated reticulocyte index imply?
Causes? |
Implies BM capable of appropriately responding to anemia (BM is healthy)
Causes: acute bleeding, hemolytic anemia |
|
|
What does a normal or low reticulocyte count--in face of anemia--imply?
Causes? |
Implies impaired BM unable to inc RBC production in setting of anemia
Causes: nutritional deficiency (Fe, B12, folate) Marrow replaced by tumor (lymphoma, leukemia) Dec'd stem cells (aplastic anemia) |
|
|
When are BM exams performed?
Site of exam? |
Low retic count, cause of anemia not clear from prelim tests
Site: posterior iliac crest |
|
|
Physiologic responses to anemia.
|
Volume retention (immediate)
Inc'd cardiac output (immediate) Right shift to O2 dissocn curve (rapid) Erythropoiesis |
