Question 1

Which of the following is true of red cell precursors as they mature?&#10;A)The nuclear-to-cytoplasmic ratio increases.&#10;B)The cells become larger.&#10;C)The cytoplasm becomes less basophilic.&#10;D)The nucleoli become more prominent.

Accepted Answer

In general,basophilia decrease as the red cell matures (one exception to this: the basophilic normoblast is characteristically more basophilic than its precursor,the pronormoblast).The nuclear-to-cytoplasmic ratio actually decreases,the cells become smaller,and nucleoli become less prominent and eventually disappear.

Question 2

What is the main site for iron storage in the bone marrow?&#10;A)stem cells&#10;B)transferrin molecules&#10;C)endothelial cells&#10;D)macrophages

Accepted Answer

Macrophages are the primary site for storage of iron in the bone marrow.Stem cells of various kinds are precursors to blood cells.Transferrin is the protein that binds and transports iron to either storage or developing red blood cells (RBCs).Endothelial cells are the lining cells of the bone marrow and blood vessels.

Question 3

Erythropoietin increases the number of red cells by all of the following mechanisms except&#10;A)prolonging cell life span.&#10;B)shortening cell division times.&#10;C)allowing earlier cell egress from the bone marrow.&#10;D)increasing the rate of hemoglobin synthesis.

Accepted Answer

Erythropoietin has no effect on red cell life span.It does perform all the other functions listed.

Question 4

What mechanism is responsible for the destruction of the majority of normal senescent erythrocytes?&#10;A)intravascular hemolysis&#10;B)rupture by complement&#10;C)phagocytosis by peripheral neutrophils&#10;D)phagocytosis by splenic macrophages

Accepted Answer

As red cells become old (senescent),changes occur in the membrane and intracellularly that lead to their phagocytosis by macrophages in the spleen.

Question 5

Which of the following correctly describes a normal mature erythrocyte?&#10;A)a 7- to 8-mm biconcave disc that lives 120 days&#10;B)a 7- to 8-mm spheroid that lives 120 days&#10;C)a 12- to 15-mm spheroid that lives 80 days&#10;D)a 12- to 15-mm biconcave disc that lives 80 days

Accepted Answer

A normal mature red cell has a diameter of 7 to 8 mm,is biconcave,and lives 120 days in circulation.

Question 6

Abnormal concentrations of cations inside erythrocytes cause&#10;A)spherocytosis.&#10;B)senescence.&#10;C)prolongation of survival.&#10;D)sickling.

Accepted Answer

Red cells have a high concentration of potassium and a low concentration of sodium when compared with the plasma environment.To maintain this difference in gradient,adenosine triphosphate (ATP)-dependent enzymes are needed.When this system fails,sodium increases and potassium falls in the red cells.This results in loss of selective permeability of the red cell membrane,and water enters the cell causing it to sphere.Senescence is a normal aging process that eventually leads to red cell phagocytosis by splenic macrophages.

Question 7

Where is erythropoietin synthesized?&#10;A)bone marrow&#10;B)kidney&#10;C)lymph nodes&#10;D)spleen

Accepted Answer

Erythropoietin is synthesized primarily in the kidney.A very small amount is produced in the liver.

Question 8

Depletion of serum haptoglobin indicates&#10;A)decreased erythropoiesis.&#10;B)extravascular hemolysis.&#10;C)intravascular hemolysis.&#10;D)increased phagocytosis of macrophages.

Accepted Answer

Haptoglobin is a plasma protein that binds any free hemoglobin in plasma after red cells are lysed in circulation.This helps salvage the iron in the hemoglobin so that it is not lost.When significant intravascular hemolysis (lysis in the blood)exists,haptoglobin is depleted;this can be measured in plasma.

Question 9

Which of the following has a pyknotic nucleus?&#10;A)pronormoblast&#10;B)basophilic normoblast&#10;C)polychromatophilic normoblast&#10;D)orthochromic normoblast

Accepted Answer

The orthochromic normoblast has a pyknotic nucleus,meaning that the chromatin is fully condensed.After this stage,the cell no longer needs the nucleus and it is extruded or expelled.The nucleus of the pronormoblast is diffuse (dispersed),that of the basophilic is beginning to show some condensing,and that of the polychromatophilic is condensing even more.

Question 10

Programmed cell death is called&#10;A)necrosis.&#10;B)apoptosis.&#10;C)hemolysis.&#10;D)phagocytosis.

Accepted Answer

Apoptosis is programmed cell death,a normal physiologic process to remove damaged,abnormal,or unneeded cells.Necrosis is abnormal death because of trauma or damage.Hemolysis is cell death by rupture (which is abnormal).Phagocytosis is the primary mechanism for removal of senescent cells,but it also can remove damaged cells.

Question 11

Why do men typically have higher erythrocyte counts than women?&#10;A)They weigh more and have more blood vessels.&#10;B)They do not lose as much blood each month.&#10;C)Testosterone stimulates erythropoiesis.&#10;D)They have more oxygen in their blood.

Accepted Answer

The answer of Why do men typically have higher erythrocyte...

Question 12

When compared with mature erythrocytes,reticulocytes&#10;A)are larger and bluer on Wright stain from remnant ribonucleic acid (RNA).&#10;B)are larger and have more vacuoles on Wright stain from remnant deoxyribonucleic acid (DNA).&#10;C)stain pinker with new methylene blue.&#10;D)still have a nucleus.

Accepted Answer

The answer of When compared with mature erythrocytes,reticulocytes&#10;A)are larger and...

Question 13

What stimulates production of erythropoietin?&#10;A)decreased red cell number in the bone marrow&#10;B)increased peripheral red cell number&#10;C)decreased iron stores&#10;D)decreased oxygen level in tissue

Accepted Answer

The answer of What stimulates production of erythropoietin?&#10;A)decreased red cell...

Question 14

The breakdown products of heme go through several biochemical degradations to form&#10;A)bilirubin.&#10;B)protoporphyrin.&#10;C)amino acids.&#10;D)haptoglobin.

Accepted Answer

The answer of The breakdown products of heme go through...

Deck 8: Erythrocyte Production and Destruction