Predominant site of erythropoiesis during 6th month of gestation is?
**Core Concept**
Erythropoiesis is the process of red blood cell production, and during fetal development, it shifts from the yolk sac to the liver and spleen. The liver is the primary site of erythropoiesis from the 3rd month to the 6th month of gestation. This transition is crucial for the production of sufficient red blood cells to meet the increasing oxygen demands of the growing fetus.
**Why the Correct Answer is Right**
The correct answer is the liver because it is the primary site of erythropoiesis during the 6th month of gestation. The liver contains a large number of hematopoietic cells, including erythroblasts, which produce red blood cells. The erythropoietin produced by the fetal liver stimulates the production of red blood cells, which are essential for the fetus's oxygen supply. The liver's role in erythropoiesis is a critical aspect of fetal development.
**Why Each Wrong Option is Incorrect**
**Option A:** The yolk sac is the primary site of erythropoiesis during the first 2 months of gestation, not the 6th month.
**Option B:** The spleen becomes involved in erythropoiesis later in fetal development, around the 7th month, and is not the primary site during the 6th month.
**Option C:** The bone marrow begins to produce red blood cells after birth and is not the primary site of erythropoiesis during fetal development.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that erythropoiesis shifts from the yolk sac to the liver and spleen during fetal development, with the liver being the primary site of erythropoiesis from the 3rd to the 6th month of gestation.
**Correct Answer:** C. Spleen