Osteoblasts are cells that lay down new bone tissue. They are found in the innermost layer of our bones, called the osteogenic or bone-forming layer. These cells are responsible for the growth and repair of our skeleton.
When we are born, our bones are made up mostly of a soft, spongy material called collagen. This gives them the flexibility to grow as we do. As we age, osteoblasts replace this collagen with harder minerals like calcium and phosphorus, which makes our bones stronger and less likely to break.
Osteoblasts also play an important role in repairing damage to our bones. When a bone is broken or damaged by disease, osteoblasts rush to the site of injury and begin laying down new bone tissue.
There are three types of osteoblasts:
1) Embryonic osteoblasts – these cells develop into other kinds of bone cells during fetal development
2) Adult osteoblasts – these cells make up the lining of allbones and produce new bone tissue throughout our lives
3) Bone marrow stromal cells – these give rise to both adult osteocytes (bone cells) and adipocytes (fat cells)