What are former osteoblasts that line the surface of bone known as?

• A. Osteocytes
• B. Lining cells
• C. Osteoclasts
• D. Matrix cells

Answer: (B)

Former osteoblasts that line the surface of bone are known as lining cells. Osteoblasts are cells responsible for the formation of new bone tissue. Once they have completed their role in laying down bone matrix, they become flattened and take on a different role by becoming lining cells. These cells are vital for bone homeostasis as they play a role in regulating the exchange of minerals and can also help in the recruitment of osteoclasts for bone resorption when necessary. This function is crucial for maintaining bone health and adapting to mechanical stress.

Osteocytes, on the other hand, are mature bone cells derived from osteoblasts that become encased in bone matrix. Osteoclasts are large cells that break down bone tissue, and matrix cells is not a recognized term in bone physiology. Understanding the distinction and the specific roles of these cells is essential for comprehending how bones are structured and maintained.