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Flashcards in Zlotnik 3 Deck (21):
1

What are some characteristics of RBC (erythrocytes)?

-contain Hb to bind oxygen (redder is more O2)
-develop in BM and live for 120 days
-biconcave with no organelles nor nucleus
-normochromic is stain normally; hypochromic is stain lighter

2

What are the diff red cell indices?

Hematocrit (packed cell volume) volume occupied by RBC (45% men, 40% women)

mean corpuscular volume (mean cell volume): avg volume of single RBCs (~85 femtoliters)

Mean corpuscular hemoglobin: avg mass of Hb in each RBC (~30pg/cell)

Mean corpuscular Hb concentration (MCHC): avg concentration of Hb in a given volume of RBCs. [Hb]/hematocrit

3

Normal range of blood cell values?

See slide 6 of lec 3

4

At what stage of erythropoiesis does Hb syn begin? Denucleation?

Proerythroblast, orthochromatic erythroblast

5

What is the # of reticulocytes important?

Measure of BM fxn
Decreased #: hematopoiesis deficient
Increased #: increase hematopoiesis, maybe in response to bleeding

6

What is erythropoietin

-a cytokine
-90% produced in KIDNEY, 10% in liver
-released in response to decreased oxygenation (change altitude, anemia, etc.)
-encourages production of RBC
-EPO deficiency: chronic renal failure, or exposed to increased O2 content
-EPO increase: renal cell carcinoma (kidney cancer), EPO doping

7

Where is the oxygen sensor?

In kidney, stimulates release of erythropoietin

8

How do we treat chronic renal failure in terms of EPO? What happens during excessive EPO?

Treat with recombinant EPO

-increased EPO, increases RBC -> thicker blood (can clog capillaries, cause heart attacks, precipitate strokes, etc.) -> result of EPO doping in some cases

9

Polycythemia? Physiological polycythemia? Secondary polycythemia? Polycythemia vera?

Polycythemia: increase in RBC proportion (elevated hematocrit); increase blood viscosity; hematocrit >55%

Physiological polycythemia: high altitude increases EPO

Secondary polycythemia: when EPO rises in kidney cancer, or EPO doping

Polycythemia vera: disease due to over-production of RBCs, erythroblasts may be hypersensitive to EPO (so maybe low EPO)

10

Every thousand meters decreases oxygen % by how much?

10%....1000 = 90%, 2000m = 80%, etc.

11

Where is iron absorbed? What carrier protein? What enhances/inhibits iron take up?

Absorbed in duodenum
-carried by iron-transferrin
-ascorbate, citrate (+)
-antacids, tetracyclin, cipro (-)

12

What is Crohn's disease?

Damage to intestinal wall (autoimmune inflammatory), reduces iron absorption

13

Where does the iron go?

Mostly to liver and into RBCs.
-some to muscles and macrophages

14

What is hemoglobin comprised of?

Heme + globin

15

What is ferritin for?

Iron storage (hemosiderin too), transferrin (iron transfer)

16

What is the most common anemia?

Iron deficiency anemia

17

What causes iron deficiency?

-decreased intake
-increased utilization (ie pregnant)
-increased loss (blood loss, menstruation, etc.)

18

What is microcytic hypochromic anemia?

-decreased iron -> decreased heme -> dec Hb -> dec oxyhemoglobin -> dec total arterial oxygen
-oxygen extraction by tissues increases to compensate
-EPO lvls rise to compensate
-result is non-viable RBC that is hypochromic because of reduced Hb and small (microcytic)

IRON DEFICIENCY CAUSES MICROCYTIC HYPOCHROMIC ANEMIA

19

What are some indications of iron deficiency?

Glossitis (swollen tongue), koilonychia (spoon shaped nails, slow growing), angular stomatitis (irritation of corner of lip)

20

Treatment of Fe deficiency?

Ferrous salts, ascorbic acid, injected

DONT GIVE WITH ANTACIDS

21

What is siderosis?

Iron storage disorders

local hemosiderosis: hemorrhage, macrophage engul RBCs and degrade HB producing hemosiderin

transfusion: too many transfusions

hemolytic: seen in hemolytic anemias, causes release of iron from RBCs

nutritional: from pots used to cook

primary: genetic disease; increased iron absorption