chapter 5 review questions

the progression of erythropoiesis from prenatal life to adulthood is

yolk sac - liver / spleen - red bone marrow

which of the following is/are characteristic of erythropoietin?

• glycoprotein

• secreted by the liver

• secreted by the kidneys

which of the following is a characteristic of erythropoietin

produced primarily in the liver of the unborn

stimulation of erythropoietin is caused by

tissue hypoxia

maturational sequences of an erythrocyte are

• rubriblast - prorubricyte - rubricyte - metarubricyte - reticulocyte

• pronormboblast - basophilic normoblast - polychromatic normoblast - orthochromatic normoblast - reticulocyte

what is the immature erythrocyte found in the bone marrow with the following characteristics:

• 12 -17um diameter

• n:c 4:1

• nucleoli not usually apparent

• basophilic cytoplasm

prorubricyte (basophilic normoblast)

nucleated erythrocyte with a reddish-pink cytoplasm and condensed chromatin pattern is a

metarubricyte (orthochromatic normoblast)

with a normal diet, an erythrocyte remains in the reticulocyte stage in the circulating blood for

1 d

in a wright stained peripheral blood smear, the reticulocyte will have a blue appearance - referred to as

polychromatophilia

in the reticulocyte stage of erythrocytic development …

• rna is catabolized and ribosomes disintegrate

• full hemoglobinization of the cell occurs

increased erythropoietin production in secondary polycythemia can be caused by

• chronic lung dz

• smoking

• renal neoplasms

what level of serum erythropoietin would you expect with pt w/ lab data:

• rbc 2.5 × 10¹² / L

• hct 24%

• hgb 8.0 g / dL

decreased

what is the cause of pt’s anemia

lack of adequate epo stimulation

relative polycythemia exists when

the plasma vol is decr

characteristic of megaloblastic maturation

nuclear maturation lags behind cytoplasmic maturation

incr amounts of 2,3-dpg _ the oxygen affinity of the hemoglobin molecule

decr

after a molecule of hemoglobin gains the first two oxygen molecules, the molecule

expels 2,3-dpg

limited metabolic ability of erythrocytes is owing to

no mitochondria for oxidative metabolism

what is true about erythrocytic cytoplasmic contents

high potassium ion

contain glucose and enzymes necessary for glycolysis

embden-meyerhof glycolytic pathway uses _ % of the erythrocyte’s total glucose

90

embden-meyerhof pathway net gain of atp provides high every phosphates to

• maintain membrane lipids

• power the cation pump needed for the sodium-potassium conc pump and calc flux

• preserve the shape and flexibility of the cellular membrane

end product of embden-meyerhof pathway of glucose metabolism in the erythrocyte is

lactate

net gain of atp in the embden-meyerhof glycolytic pathway is

2

the most common erythrocytic enzyme deficiency involving the embden-meyerhof glycolytic pathway is a deficiency of

pyruvate kinase

if a defect in the oxidative pathway (hexose monophosphate shunt) occurs, what will result

• insufficient amounts of reduced glutathione

• denaturation of globin

• precipitation of heinz bodies

function of the methemoglobin reductase pathway

prevent oxidation of heme iron

to maintain reduced levels of methemoglobin in the red blood cell, what chemical is necessary to maintain heme iron in a functional 2+ state

nadh

why would a pt have heinz bodies in rbc

reduced amounts of glutathione

luebering-rapoport pathway

permits the accumulation of 2,3-dpg

in conditions of acidosis,

erythrocytic glycolysis is reduced

as erythrocyte ages,

enzyme activity, particularly glycolysis, decreases

extravascular rbc destruction occurs in

macrophages of the spleen