RBC CHaPTER 3 Flashcards Preview

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Flashcards in RBC CHaPTER 3 Deck (42):
1

OUTER LEAFLET lipids

PC sphingomyelin

2

inner leaflet lipids

Phos Iniositol, Ethanolamine, and serine

3

Flippase

maintains leaflet distributionof lipids. In senescent cells PS shifts to outer leaflet marking for destruction

4

Heinz Body

Deoxygenized nonfunctional hemoglobin bound to band 3.

5

Spectrin Ratio

horizontal interactions. More tetramers : dimers means more stability.

6

Ankyrin and Protein 4.2

attach spectrin to Band 3

7

Protein 4.1

attach spetrin to glycophorin C

8

Damaged RBCs

give off microvessicles leading to a spherocyte

9

Echninocytes

Spikey, expansion of outer leaflet

10

LCAT

esterifies cholesterol, preventing it from becoming part of the reb blood cell membrane. Only unesterified cholesterol in membrane. Leads to acanthocyte

11

Stomatocyte

expansion of inner leaflet.

12

Acive transport of calcium

out of cell. Too much Ca2+ causes crosslinking.

13

Glycolytic Pathway

glucose produces ATP.

14

Methhemoglobin reductase

protects hemoglobin from oxidation via NaDH and MHR.

15

Hexose monophosphate shunt

provides NADPH and GSH to reduce oxidants

16

Rppoport Leubering Pathway

Produces BPG o affect hemoglobin oxygen affinity

17

RBC progenator development

BUFE-> CFU E. BFU E responds to IL3 and GMCSF. CFU-E responds EPO.

18

erythroblast

morphological distinguishable RBC in marrow with a nucleus

19

reticulocyte

pinched off nucleus

20

4 RBC blast stages

pronormoblast, basophillic normoblast, polychromatophillic normoblast, orthochromic normoblast

21

RBC development characteristics

decrease in N:C ration, initially nucleus is all of pronormoblast. Lacey to compact and darker. BLuish and basophillic to pink and acidophillic due to presence of hemoglobin.

22

Reticulocyte stain

Nucleus gone, but remaining blue from RNA and mitochondria.

23

Siderocytes

reticulocyte or beyond contain iron granules identifiable by Prussian Blue.

24

Sideroblast

blast with iron deposits

25

shift or stress reticulocytes

released early.

26

EPO effects

stimulates bfu and cfu to divide and mature. increases rate of hemoglobin and mRNA generation. decreasesnormoblast maturation time. increases rate of enuclation. stimulates shift reticulocytes.

27

Extravascular hemoglobin destruction pathway

Heme + globin -> biliverdin + CO + Fe -> billirubin > billirubin - Albumin -> to liver. Bilirubin diglucornide -> urobilinogen -> stoolor blood and kidney.

28

compare contrast cfu e bfu e

bfu e more quiescent higher prolifertive capacity, more responive to early acting cytokines IL 3 GMCSF, cfu e more responsive to EPO

29

normal reticulocyte concentration

.5-2% RBC in peripheral blood

30

esterified cholesterol

(LCAT). Esterified plasma cholesterol cannot exchange with the red cell membrane. When LCAT is absent (congenital LCAT deficiency or hepatocellular disease), free plasma cholesterol increases, resulting in accumulation of cholesterol within erythrocyte membranes and RBC membrane surface area expansion. An excess of cell membrane due to proportional increases in cholesterol and phospholipids, maintaining the normal ratio, results in the formation of macrocodocytes (large target cells).

31

stomatocyte

expansion inner leaflet

32

zeta potential

comes from glycophorin extracellular domain glycosylation, repulses RBCs.

33

band 3

anion exchange protein Cl - HCO3- exchange. Binds Denatured hemoglobin greater than regular.

34

ankyrin

is a large protein that serves as the high-affinity binding site for the attachment of spectrin to the inner membrane surface. Ankyrin binds spectrin near the region involved in dimer–tetramer associations. In turn, ankyrin is bound with high affinity to the cytoplasmic portion of band 3 (the anchor for the membrane skeleton). 15 Band 4.2 binds to ankyrin and band 3, strengthening their interaction and helping to bind the skeleton to the lipid bilayer at its major attachment point.
Kindle Edition.

35

actin

These short filaments are stabilized by their interactions with other proteins of the red cell skeleton including tropomodulin, adducin, tropomyosin, and band 4.9. Spectrin dimers bind to actin filaments near the tail end of the spectrin dimer. Band 4.1 interacts with spectrin and actin and with GPC in the overlying lipid bilayer. It serves to stabilize the otherwise weak interaction between spectrin and actin and is necessary for normal membrane stability. 8 This complex of spectrin, actin, tropomodulin, tropomyosin, adducin, band 4.9, and band 4.1 serves as the secondary attachment point for the red cell skeleton, binding to GPC of the membrane.

36

RBC ion concentration

very low sodium and calcium compared to plasma, higher potassium magnesium

37

cyanosis

(a bluish discoloration of the skin due to an increased concentration of deoxyhemoglobin in the blood).

38

epo function

Stimulates BFU-E and CFU-E to divide and mature Increases rate of mRNA and protein (hemoglobin) synthesis Decreases normoblast maturation time Increases rate of enucleation (extrusion of nucleus) Stimulates early release of bone marrow reticulocytes (shift reticulocytes)

39

hypocis hif1

hypoxia trggers HIF1 ginds to EPO promoter element

40

main EPO function

progenators which require high EPO die, but during hypoxia are rescued from apoptosis

41

EPO signaling cascade

JAK stat

42

RBC destruction

accumulation of PS on outer membrane, decreased ATP production and glucose accumulation especially in the spleen leads to osmotic fragility due to decreased cation pump action, oxidized membrane proteins decrease deromability, IGG accumulates on membrane all triggering splenic macrophages.