What tissue covers bone with a double-layered structure that nourishes bone tissue?

What tissue covers bone with a double-layered structure that nourishes bone tissue?

• A. Periosteum
• B. Endosteum
• C. Epimysium
• D. Perichondrium

Answer: (A)

The periosteum is the tissue that covers bone with a double-layered structure and nourishes bone tissue. Its outer fibrous layer provides protection and attachment to the bone, while the inner osteogenic (or cambial) layer contains osteoblasts and osteoprogenitor cells that can form new bone and help in repair. Blood vessels and nerves run through the periosteum, delivering nutrients to the bone matrix and the bone cells. The endosteum lines the inner surfaces of bone and is thinner and not described as having this distinct double-layered structure, while perichondrium covers cartilage and epimysium surrounds muscle. So the nourishing, double-layered covering is the periosteum.

The periosteum is the tissue that covers bone with a double-layered structure and nourishes bone tissue. Its outer fibrous layer provides protection and attachment to the bone, while the inner osteogenic (or cambial) layer contains osteoblasts and osteoprogenitor cells that can form new bone and help in repair. Blood vessels and nerves run through the periosteum, delivering nutrients to the bone matrix and the bone cells. The endosteum lines the inner surfaces of bone and is thinner and not described as having this distinct double-layered structure, while perichondrium covers cartilage and epimysium surrounds muscle. So the nourishing, double-layered covering is the periosteum.