What is one possible site of extramedullary hematopoiesis in times of increased blood cell production?

What is one possible site of extramedullary hematopoiesis in times of increased blood cell production?

• A. Spleen
• B. Kidney
• C. Umbilicus
• D. Bone cortex

Answer: (A)

During times when the bone marrow can’t meet the body's demand for blood cells, hematopoiesis can occur outside the marrow. The spleen provides a ready environment with red pulp that can support production of blood elements, so it becomes a site of extramedullary hematopoiesis when demand is high. This makes the spleen the best choice among the options. The kidney is not a typical site for new blood-cell production in this context, the umbilicus isn’t involved in hematopoiesis in adults, and the bone cortex does not contain active hematopoietic tissue (hematopoiesis occurs in the marrow within the medullary cavity).

During times when the bone marrow can’t meet the body's demand for blood cells, hematopoiesis can occur outside the marrow. The spleen provides a ready environment with red pulp that can support production of blood elements, so it becomes a site of extramedullary hematopoiesis when demand is high. This makes the spleen the best choice among the options. The kidney is not a typical site for new blood-cell production in this context, the umbilicus isn’t involved in hematopoiesis in adults, and the bone cortex does not contain active hematopoietic tissue (hematopoiesis occurs in the marrow within the medullary cavity).