RBC CHaPTER 3

Question 1

OUTER LEAFLET lipids

Answer 1

PC sphingomyelin

Question 2

inner leaflet lipids

Answer 2

Phos Iniositol, Ethanolamine, and serine

Question 3

Flippase

Answer 3

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

Question 4

Heinz Body

Answer 4

Deoxygenized nonfunctional hemoglobin bound to band 3.

Question 5

Spectrin Ratio

Answer 5

horizontal interactions. More tetramers : dimers means more stability.

Question 6

Ankyrin and Protein 4.2

Answer 6

attach spectrin to Band 3

Question 7

Protein 4.1

Answer 7

attach spetrin to glycophorin C

Question 8

Damaged RBCs

Answer 8

give off microvessicles leading to a spherocyte

Question 9

Echninocytes

Answer 9

Spikey, expansion of outer leaflet

Question 10

LCAT

Answer 10

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

Question 11

Stomatocyte

Answer 11

expansion of inner leaflet.

Question 12

Acive transport of calcium

Answer 12

out of cell. Too much Ca2+ causes crosslinking.

Question 13

Glycolytic Pathway

Answer 13

glucose produces ATP.

Question 14

Methhemoglobin reductase

Answer 14

protects hemoglobin from oxidation via NaDH and MHR.

Question 15

Hexose monophosphate shunt

Answer 15

provides NADPH and GSH to reduce oxidants

Question 16

Rppoport Leubering Pathway

Answer 16

Produces BPG o affect hemoglobin oxygen affinity

Question 17

RBC progenator development

Answer 17

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

Question 18

erythroblast

Answer 18

morphological distinguishable RBC in marrow with a nucleus

Question 19

reticulocyte

Answer 19

pinched off nucleus

Question 20

4 RBC blast stages

Answer 20

pronormoblast, basophillic normoblast, polychromatophillic normoblast, orthochromic normoblast

Question 21

RBC development characteristics

Answer 21

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.

Question 22

Reticulocyte stain

Answer 22

Nucleus gone, but remaining blue from RNA and mitochondria.

Question 23

Siderocytes

Answer 23

reticulocyte or beyond contain iron granules identifiable by Prussian Blue.

Question 24

Sideroblast

Answer 24

blast with iron deposits

Question 25

shift or stress reticulocytes

Answer 25

released early.

Question 26

EPO effects

Answer 26

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.

Question 27

Extravascular hemoglobin destruction pathway

Answer 27

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

Question 28

compare contrast cfu e bfu e

Answer 28

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

Question 29

normal reticulocyte concentration

Answer 29

.5-2% RBC in peripheral blood

Question 30

esterified cholesterol

Answer 30

(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).

Question 31

stomatocyte

Answer 31

expansion inner leaflet

Question 32

zeta potential

Answer 32

comes from glycophorin extracellular domain glycosylation, repulses RBCs.

Question 33

band 3

Answer 33

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

Question 34

ankyrin

Answer 34

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.

Question 35

actin

Answer 35

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.

Question 36

RBC ion concentration

Answer 36

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

Question 37

cyanosis

Answer 37

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

Question 38

epo function

Answer 38

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)

Question 39

hypocis hif1

Answer 39

hypoxia trggers HIF1 ginds to EPO promoter element

Question 40

main EPO function

Answer 40

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

Question 41

EPO signaling cascade

Answer 41

JAK stat

Question 42

RBC destruction

Answer 42

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.