During times of increased blood cell production, an extramedullary site of hematopoiesis may be the?

During times of increased blood cell production, an extramedullary site of hematopoiesis may be the?

• A. Liver
• B. Lung
• C. Brain
• D. Spleen

Answer: (D)

When the bone marrow can’t keep up with the body’s need for blood cells, other organs can step in to produce them. The spleen is a classic extramedullary hematopoietic site because its red pulp provides a supportive environment where erythroid and other blood cells can mature when demand is high or marrow function is impaired. The liver can do this too, especially during fetal life or certain disease states, but in adults the spleen is the most typical secondary site referenced for extramedullary hematopoiesis. The lungs and brain don’t normally generate blood cells, so they aren’t considered sites of hematopoiesis.

When the bone marrow can’t keep up with the body’s need for blood cells, other organs can step in to produce them. The spleen is a classic extramedullary hematopoietic site because its red pulp provides a supportive environment where erythroid and other blood cells can mature when demand is high or marrow function is impaired. The liver can do this too, especially during fetal life or certain disease states, but in adults the spleen is the most typical secondary site referenced for extramedullary hematopoiesis. The lungs and brain don’t normally generate blood cells, so they aren’t considered sites of hematopoiesis.