A plan for--or a summary of--a writing project or speech. An outline is usually in the form of a list divided into headings and subheadings that distinguish main points from supporting points. Most word processors contain an outlining feature that allows writers to format outlines automatically.
Osteoblasts are bone-forming cells that descend from osteoprogenitor cells. They form a protein mixture known as osteoid, which mineralizes to become bone. Osteoid is primarily composed of Type I collagen.Osteoblasts also manufacture hormones, such as prostaglandins, to act on the bone itself.steocytes: Osteocytes are mature bone cells that originate from osteoblasts, which have migrated into and become trapped and surrounded by bone matrix, produced by themselves. The spaces they occupy are known as lacunae.
Osteoprogenitor Cells. These are immature cells that are primarily located in the bone marrow and periosteum (membrane that lines the surface of all bones). They mature into the osteoblasts, another type of bone cell.steoblast Cells. These are the bone cells that are primarily responsible for bone formation. They only have one nucleus and are derived from osteoprogenitor cells. They function by secreting a substance called osteoid, which is also known as the bone matrix.