Osteoid

 ( Proteins ) 

In histology, osteoid is the unmineralized, organic portion of the bone matrix that forms prior to the maturation of Osseous tissue. begin the process of forming bone tissue by secreting the osteoid as several specific . The osteoid and its adjacent bone cells have developed into new bone tissue when it becomes mineralized.

Osteoid makes up about fifty percent of bone volume and forty percent of bone weight. It is composed of Fibrous protein and ground substance. The predominant type of fiber is type I collagen and comprises ninety percent of the osteoid. The ground substance is mostly made up of chondroitin sulfate and osteocalcin.

---

Disorders When there are insufficient nutrient minerals or osteoblast dysfunction, the osteoid does not mineralize properly and accumulates. The resultant disorder is termed rickets in children and osteomalacia in adults. A deficiency of type I collagen, such as in osteogenesis imperfecta, also leads to defective osteoid and brittle, fracture-prone bones.

In some cases, secondary hyperparathyroidism can cause a disturbance in mineralisation of calcium and phosphate.

Another condition is a disturbance in primitive transformed cells of mesenchymal origin, which exhibit osteoblastic differentiation and produce malignant osteoid. This results in the formation of a malignant primary bone tumor known as osteosarcoma or osteogenic sarcoma. This malignancy most often develops in adolescence during periods of rapid osteoid formation (commonly referred to as growth spurts).

• Jaffe, N. (2025). 9781441902832, Springer. ISBN 9781441902832

---

External links

• - "Bone, femur"
• Dr. Susan Ott's website on osteomalacia

Post Comment