Which layer of the periosteum contains osteogenic cells?

Which layer of the periosteum contains osteogenic cells?

• A. Fibrous Outer Layer
• B. Inner Osteogenic Layer
• C. Endosteum
• D. Perichondrium

Answer: (B)

The inner, cellular layer of the periosteum contains osteogenic cells. This inner osteogenic (cambium) layer houses osteoprogenitor cells that can differentiate into osteoblasts, supporting bone growth in diameter and repair after injury. The outer fibrous layer is dense connective tissue with fibroblasts and collagen but lacks these osteogenic cells, so it doesn’t contribute to new bone formation. The endosteum lines the inner bone surfaces, and while it also has osteogenic cells, it is not part of the periosteum. The perichondrium surrounds cartilage, not bone, so it isn’t the layer involved in periosteal osteogenesis.

The inner, cellular layer of the periosteum contains osteogenic cells. This inner osteogenic (cambium) layer houses osteoprogenitor cells that can differentiate into osteoblasts, supporting bone growth in diameter and repair after injury. The outer fibrous layer is dense connective tissue with fibroblasts and collagen but lacks these osteogenic cells, so it doesn’t contribute to new bone formation. The endosteum lines the inner bone surfaces, and while it also has osteogenic cells, it is not part of the periosteum. The perichondrium surrounds cartilage, not bone, so it isn’t the layer involved in periosteal osteogenesis.