What large cell with multiple separate nuclei is found in bone marrow?

What large cell with multiple separate nuclei is found in bone marrow?

• A. Osteoblast
• B. Megakaryocyte
• C. Osteoclast
• D. Monoblast

Answer: (C)

Osteoclasts are large multinucleated cells formed by fusion of monocyte-macrophage lineage cells. Their many nuclei let them coordinate extensive bone resorption on a bone surface, which is essential for remodeling and calcium homeostasis. The cells sit on bone and create a sealed zone with a ruffled border, secreting acid and proteolytic enzymes to dissolve mineral and matrix. Megakaryocytes are indeed large bone-marrow cells, but their nucleus is lobulated within a single cell rather than truly multiple separate nuclei. Osteoblasts are bone-forming, usually single-nucleated cells. Monoblasts are precursors to monocytes and are not multinucleated large bone-resorbing cells. So the large multinucleated cell found associated with bone remodeling is the osteoclast.

Osteoclasts are large multinucleated cells formed by fusion of monocyte-macrophage lineage cells. Their many nuclei let them coordinate extensive bone resorption on a bone surface, which is essential for remodeling and calcium homeostasis. The cells sit on bone and create a sealed zone with a ruffled border, secreting acid and proteolytic enzymes to dissolve mineral and matrix.

Megakaryocytes are indeed large bone-marrow cells, but their nucleus is lobulated within a single cell rather than truly multiple separate nuclei. Osteoblasts are bone-forming, usually single-nucleated cells. Monoblasts are precursors to monocytes and are not multinucleated large bone-resorbing cells.

So the large multinucleated cell found associated with bone remodeling is the osteoclast.