What physiologic defect is responsible for causing anemia? a. ...

[CBme]

What physiologic defect is responsible for causing anemia?
 
  a. Increased blood viscosity
  b. Depressed hematopoietic system
  c. Presence of abnormal hemoglobin
  d. Decreased oxygen-carrying capacity of blood

Question 2

The regulation of red blood cell (RBC) production is thought to be controlled by which physiologic factor?
 
  a. Hemoglobin
  b. Tissue hypoxia
  c. Reticulocyte count
  d. Number of RBCs

[katheyjon]

Answer to Question 1

ANS: D
Anemia is a condition in which the number of red blood cells or hemoglobin concentration is reduced below the normal values for age. This results in a decreased oxygen-carrying capacity of blood. Increased blood viscosity is usually a function of too many cells or of dehydration, not of anemia. A depressed hematopoietic system or abnormal hemoglobin can contribute to anemia, but the definition depends on the decreased oxygen-carrying capacity of the blood.

Answer to Question 2

ANS: B
Hemoglobin does not directly control RBC production. If there is insufficient hemoglobin to adequately oxygenate the tissue, then erythropoietin may be released. When tissue hypoxia occurs, the kidneys release erythropoietin into the bloodstream. This stimulates the marrow to produce new RBCs. Reticulocytes are immature RBCs. The retic count can be used to monitor hematopoiesis. The number of RBCs does not directly control production. In congenital cardiac disorders with mixed blood flow or decreased pulmonary blood flow, RBC production continues secondary to tissue hypoxia.

[CBme]

Excellent

[bdobbins]

TYSM