Osteoblasts are responsible for which function in bone tissue?

• A. Forming bone by secreting osteoid and promoting mineralization
• B. Resorbing bone matrix with acids
• C. Maintaining mature bone cells in lacunae
• D. Resorbing cartilage

Answer: (A)

Osteoblasts are the bone builders. They synthesize the organic matrix of bone, called osteoid, which is mainly collagen, and then promote mineralization by attracting calcium and phosphate to crystallize as hydroxyapatite. This combination of organic matrix production and mineral deposition is how new bone tissue is formed and how bone repair proceeds. The other cells don’t perform this building role: osteoclasts resorb bone, osteocytes maintain mature bone within lacunae, and cartilage resorption involves different cells related to cartilage, not osteoblasts. So forming bone by secreting osteoid and promoting mineralization is exactly what osteoblasts do.