Osteoblasts are the main type of bone cells and the inactive form of these cells are called lining cells. The active form of the cells regulate the passage of calcium in and out of the bone, and they express specialized protein molecules on their membrane for responding to various hormones and stimulants.
These specialized proteins can activate another type of cells called osteoclasts. While, the third type of cells, Osteocytes also present in the bone. Interestingly, they originate from osteoblasts. Hence, the osteoblasts are represented as major bone cells. In this article, the difference between osteoblast and osteoclast has been described.
Difference between Osteoblast and Osteoclast (Osteoblast vs Osteoclast)
| S. No | Characteristics | Osteoblast | Osteoclast |
| 1 | Cell shape | Osteoblasts are cuboidal in shape. | Osteoclast cells are flat-shaped. |
| 2 | Cell size | Cells are very smaller in size (20-30 micrometers in diameter) | Cells are larger in size (150–200 µm in diameter) |
| 3 | Function | Bone formation and Maintains bone tissue integrity and shape. | Actively involved in bone resorption |
| 4 | Nucleus number | Only one nucleus (uninucleate) | Many numbers of the nucleus (multinucleated) |
| 5 | Cellular organelles | Contains a lesser number of mitochondria, vacuoles, and lysosome. | Contains a greater number of mitochondria, vacuoles, and lysosome. |
| 6 | Sealing zones | Does not contain sealing zones and ruffled borders | Contains sealing zones and ruffled borders |
| 7 | Osteoid production | Produces osteoid protein | Cannot produce osteoid protein |
| 8 | Hormone production | Produces the hormone, Prostaglandins. | Cannot produce any type of hormone. |
| 9 | Parathyroid hormone receptor | Express parathyroid (PTH) hormone receptors. | Do not express parathyroid (PTH) hormone receptors. |
| 10 | Enzyme/acid production | produces more amount of alkaline phosphatase enzyme | produces more amount of phosphatase enzyme and tartrate-resistant acid. |
| 11 | Differentiation | Differentiated from pluripotent mesenchymal stem cells | Differentiated from hematopoietic cells of granulocyte-macrophage lineage. |
| 12 | Engulfing nature | Do not engulf bone fragments | Engulfs bone fragments |
| 13 | Phagocytic nature | Equipped with a phagocytic-like mechanism | Equipped with the phagocytic-like mechanism. |
| 14 | Cytokines | Produces pro-inflammatory cytokines | Uses cytokines for conversion of macrophages to osteoclasts |
| 15 | Collagen production | Produces the collagen protein | Dissolves the collagen protein |
