Chapter 8 - Erythrocyte Production and Destruction

Question 1

Which of the following is the most mature normoblast?

Answer 1

a. Orthochromic normoblast

Question 2

Which of the following is an erythrocyte progenitor?

Answer 2

c. CFU-E

Question 3

What erythroid precursor can be described as follows: the cell is of medium size compared with other normoblasts, with an N:C ratio of nearly 1:1. The nuclear chromatin is condensed and chunky throughout the nucleus. No nucleoli are seen. The cytoplasm is a muddy, blue-pink
color.

Answer 3

d. Polychromatic normoblast

Question 4

Which of the following is not related to the effects of erythropoietin?

Answer 4

b. The formation of pores in sinusoidal endothelial cells for marrow egress

Question 5

Hypoxia stimulates RBC production by:

Answer 5

b. Stimulating EPO production by the kidney

Question 6

In the bone marrow, RBC precursors are located:

Answer 6

d. Surrounding macrophages in erythroid islands

Question 7

Which of the following determines the timing of egress of RBCs from the bone marrow?

Answer 7

a. Maturing normoblasts slowly lose receptors for adhesive molecules that bind them to stromal cells

Question 8

What single feature of normal RBCs is most responsible for limiting their life span?

Answer 8

d. Loss of the nucleus

Question 9

Intravascular or fragmentation hemolysis is the result of trauma to RBCs while in the circulation.

Answer 9

a. True

Question 10

Extravascular hemolysis occurs when:

Answer 10

c. Splenic macrophages ingest senescent cells

Question 11

A pronormoblast in its usual location belongs to the RBC mass of the body, but not to the erythron.

Answer 11

b. False

Question 12

A cell has an N:C ratio of 4:1. Which of the following statements would describe it?

Answer 12

b. The bulk of the cell is composed of nucleus.