CH 35 CLINICAL MANIFESTATIONS AND CLASSIFICATION OF ERYTHROCYTE DISORDERS

Question 1

T/F: Effects of Anemia in O2 transport

In anemia, extraction of the same amount of oxygen leads to greater hemoglobin desaturation and lower oxygen tension at the venous end of the capillary.

Answer 1

TRUE

In anemia, extraction of the same amount of oxygen leads to greater hemoglobin desaturation and lower oxygen tension at the venous end of the capillary.

(Normally: Extraction of one-fourth of this amount reduces the oxygen tension of 100 torr in the arterial end of the capillary to 40 torr in the venous end. This partial extraction ensures the presence of sufficient diffusion pressure throughout the capillaries to provide all cells with enough oxygen for the cell’s metabolic needs)

Question 2

the major regulator of EPO production

Answer 2

HIF-2

Question 3

actions include respiratory control, transcrip- tional regulation of glycolytic enzyme genes, angiogenesis, and energy metabolism

Answer 3

HIF-1

Question 4

HIFs’ downregulation is mediated by two principal
negative regulators

Answer 4

1. Von Hippel–Lindau tumor suppressor (VHL) and
2. prolyl hydroxylase domain-containing proteins (PHD)

Question 5

_____ (encoded by EGLN1) - principal PHD for regulation of erythropoiesis.

Answer 5

PHD2

Question 6

Energy metabolism at the optimal oxygen supply is sustained by energy-efficient oxidative phosphorylation.

In hypoxia, energy is produced by less efficient ____ accomplished by upregulation of transcription of glycolytic enzyme genes and increased glucose transport, a process known as the _____

Answer 6

glycolysis

Pasteur effect

Question 7

The Pasteur effect and its exception in the metabolism observed in malignant tissue, referred to as the _____, are both explained at the molecular level by changes in HIF-1 levels.

Answer 7

Warburg effect

Question 8

“Hemoglobin’s oxygen binding affinity is inversely
related both to acidity and to the concentration of carbon dioxide”

Answer 8

Bohr Effect

Question 9

T/F

Efficient increase in tissue oxygen delivery is accomplished by decrease in the affinity of hemoglobin for oxygen (right-shifted hemoglobin oxygen dissociation curve)

Answer 9

True

Question 10

T/F

In chronic anemia, there is an increase in 2-3 BPG

Answer 10

T

Question 11

In acute anemia, the major donor areas for redistribution of blood are the

Answer 11

mesenteric and iliac beds

Question 12

In chronic anemia, the major donor areas for redistribution of blood are the

Answer 12

cutaneous tissue and the kidneys

Question 13

organs with the most pressing need for oxygen

Answer 13

heart and brain

Question 14

In an otherwise healthy person, a measurable increase in resting cardiac output does not occur until hemoglobin concentration is less than _____ g/L

*signs of cardiac hyperactivity usually are not present until hemoglobin concentration reaches even lower levels

Answer 14

70

Question 15

The most appropriate response to anemia is a ____

Answer 15

compensatory increase of red cell production, which may increase about twofold to threefold acutely and fourfold to sixfold chronically, and 10-fold in the most extreme case.

Question 16

The increase in RBC production is mediated by increased production of

Answer 16

EPO