Author Question: What mechanism is responsible for the destruction of the majority of normal senescent erythrocytes? ... (Read 150 times)

formula1 · **on:** Jun 25, 2018

What mechanism is responsible for the destruction of the majority of normal senescent erythrocytes?

a. Intravascular hemolysis
b. Rupture by complement
c. Phagocytosis by peripheral neutrophils
d. Phagocytosis by splenic macrophages

Question 2

Depletion of serum haptoglobin indicates:

a. Decreased erythropoiesis
b. Extravascular hemolysis
c. Intravascular hemolysis
d. Increased phagocytosis of macrophages

Sassygurl126 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

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

Answer to Question 2

ANS: C
Haptoglobin is a plasma protein that binds any free hemoglobin in plasma after red cells lysis 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.