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

As red cell precursors mature, their cytoplasm becomes less basophilic. The nuclear-to-cytoplasmic ratio actually decreases, and the cells become smaller. The nucleoli become less prominent as well.

Question 2

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

Reticulocytes are young, immature erythrocytes that still contain remnant ribosomal RNA. This RNA gives the cell a bluish appearance on Wright stain and makes them slightly larger than mature erythrocytes. Reticulocytes do not have a nucleus, as it has been extruded during their maturation process. They also stain pinker with new methylene blue, but this is not as specific to reticulocytes as the bluish appearance on Wright stain.

Question 3

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 breakdown of heme ultimately leads to the formation of bilirubin.

Question 4

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

Only the orthochromic normoblast has a pyknotic nucleus.

Question 5

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

Depletion of serum haptoglobin is indicative of intravascular hemolysis, which occurs when red blood cells are destroyed within the bloodstream. Haptoglobin binds to free hemoglobin released from the lysed red blood cells, preventing its renal excretion and allowing it to be recycled by macrophages. Therefore, when hemolysis is occurring within blood vessels, haptoglobin levels in the serum will decrease.

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

Abnormal concentrations of cations inside erythrocytes can cause spherocytosis, which is a condition where the erythrocyte membrane becomes more rigid and spherical in shape, leading to hemolysis.

Question 7

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

Phagocytosis by splenic macrophages is the mechanism responsible for the destruction of the majority of normal senescent erythrocytes. The spleen removes old or abnormal red blood cells (RBCs) by trapping them in narrow capillaries and destroying them through phagocytosis by splenic macrophages. This process of removing senescent RBCs is known as extravascular hemolysis. Intravascular hemolysis refers to the processes that destroy red blood cells within blood vessels, but this is not the primary mechanism for the destruction of normal senescent erythrocytes. Rupture by complement and phagocytosis by peripheral neutrophils are not major mechanisms responsible for the destruction of normal senescent erythrocytes.

Question 8

Where is erythropoietin synthesized?&#10;A) Bone marrow&#10;B) Kidney&#10;C) Lymph nodes&#10;D) Spleen

Accepted Answer

Erythropoietin is mainly synthesized in the kidney, specifically in the peritubular interstitial cells in the cortex and outer medulla. It can also be produced in a small amount in the liver.

Question 9

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

Testosterone is known to stimulate erythropoiesis, the process of producing red blood cells. As men have higher levels of testosterone compared to women, this can lead to a higher erythrocyte count.

Question 10

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

Accepted Answer

A normal mature erythrocyte is a 7- to 8-micrometer biconcave disc that has a lifespan of approximately 120 days.

Question 11

Programmed cell death is called:&#10;A) Necrosis&#10;B) Apoptosis&#10;C) Hemolysis&#10;D) Phagocytosis

Accepted Answer

The answer of Programmed cell death is called:&#10;A) Necrosis&#10;B) Apoptosis&#10;C)...

Question 12

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

The answer of What is the main site for iron...

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...

Question 14

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

The answer of Erythropoietin increases the number of red cells...

Deck 8: Erythrocyte Production and Destruction