osteoblasterna

Osteoblasts are specialized cells responsible for the formation of new bone tissue. They originate from mesenchymal stem cells and play a crucial role in the process of bone remodeling, which is the continuous cycle of bone resorption and formation. Osteoblasts synthesize and secrete the organic components of bone, known as osteoid, which is primarily composed of collagen. This osteoid then undergoes mineralization, where calcium and phosphate ions are deposited, transforming it into mature bone.

These cells are found on the surfaces of bone where growth or repair is occurring. They are characterized by their cuboidal shape and their abundant endoplasmic reticulum and Golgi apparatus, which are indicative of their high rate of protein synthesis. Once osteoblasts have secreted sufficient osteoid and it has mineralized, some osteoblasts become embedded within the bone matrix they have created. At this stage, they are referred to as osteocytes, which are mature bone cells that maintain the bone tissue and sense mechanical stress. Other osteoblasts may remain on the bone surface, continuing to contribute to bone formation or participating in bone resorption by lining the surfaces. The activity of osteoblasts is regulated by various hormones, growth factors, and mechanical stimuli, ensuring that bone mass is maintained and adapted to the body's needs.