In response to anemia, erythropoietin is produced primarily by which organ?

In response to anemia, erythropoietin is produced primarily by which organ?

• A. Liver
• B. Kidney
• C. Spleen
• D. Bone marrow

Answer: (B)

The main concept is how the body detects anemia and signals for more red blood cells. Erythropoietin is the hormone that stimulates the bone marrow to increase erythropoiesis. In adults, the kidneys are the primary source of EPO. Specialized cells in the kidney’s peritubular interstitium sense low oxygen (hypoxia) and upregulate EPO production, which then travels to the bone marrow to boost RBC formation. The liver does contribute some EPO, especially in fetal life, but it is not the main source in adults. The spleen is involved in filtering and storing red cells, not producing EPO. So, in response to anemia, EPO is produced mainly by the kidney, signaling the bone marrow to ramp up red cell production.

The main concept is how the body detects anemia and signals for more red blood cells. Erythropoietin is the hormone that stimulates the bone marrow to increase erythropoiesis. In adults, the kidneys are the primary source of EPO. Specialized cells in the kidney’s peritubular interstitium sense low oxygen (hypoxia) and upregulate EPO production, which then travels to the bone marrow to boost RBC formation. The liver does contribute some EPO, especially in fetal life, but it is not the main source in adults. The spleen is involved in filtering and storing red cells, not producing EPO. So, in response to anemia, EPO is produced mainly by the kidney, signaling the bone marrow to ramp up red cell production.