Bone: the organ - periosteum and endosteum

Periosteum covers the outer surface of bones, except over articular cartilages. The periosteum consists of an outer fibrous layer of dense connective tissue and an inner osteogenic layer. Bone-lining cells in the inner layer are capable of differentiating into bone forming osteoblasts. This osteogenic layer varies considerably depending on its functional state, reflecting regions of relative inactivity, bone deposition, or bone resorption and remodeling. The periosteum is well vascularized and innervated.

Periosteum covers the outer surface of bones, except over articular cartilages. The periosteum consists of an outer fibrous layer of dense connective tissue and an inner osteogenic layer. Bone-lining cells in the inner layer are capable of differentiating into bone forming osteoblasts. This osteogenic layer varies considerably depending on its functional state, reflecting regions of relative inactivity, bone deposition, or bone resorption and remodeling. The periosteum is well vascularized and innervated.

Periosteum covers the outer surface of bones, except over articular cartilages. The periosteum consists of an outer fibrous layer of dense connective tissue and an inner osteogenic layer. Bone-lining cells in the inner layer are capable of differentiating into bone forming osteoblasts. This osteogenic layer varies considerably depending on its functional state, reflecting regions of relative inactivity, bone deposition, or bone resorption and remodeling. The periosteum is well vascularized and innervated.

Periosteum covers the outer surface of bones, except over articular cartilages. The periosteum consists of an outer fibrous layer of dense connective tissue and an inner osteogenic layer. Bone-lining cells in the inner layer are capable of differentiating into bone forming osteoblasts. This osteogenic layer varies considerably depending on its functional state, reflecting regions of relative inactivity, bone deposition, or bone resorption and remodeling. The periosteum is well vascularized and innervated.

Periosteum covers the outer surface of bones, except over articular cartilages. The periosteum consists of an outer fibrous layer of dense connective tissue and an inner osteogenic layer. Bone-lining cells in the inner layer are capable of differentiating into bone forming osteoblasts. This osteogenic layer varies considerably depending on its functional state, reflecting regions of relative inactivity, bone deposition, or bone resorption and remodeling. The periosteum is well vascularized and innervated.

The endosteum consists of single layer of bone lining cells that covers all internal bone surfaces (including spicules of spongy bone), and extends into Haversian and Volkmann’s canals. In non-active regions, these cells are squamous-shaped and include osteoprogenitor cells. In areas of active bone deposition, cuboidal osteoblasts are present; areas of bone resorption are marked by the presence of osteoclasts.

The endosteum consists of single layer of bone lining cells that covers all internal bone surfaces (including spicules of spongy bone), and extends into Haversian and Volkmann’s canals. In non-active regions, these cells are squamous-shaped and include osteoprogenitor cells. In areas of active bone deposition, cuboidal osteoblasts are present; areas of bone resorption are marked by the presence of osteoclasts.

The endosteum consists of single layer of bone lining cells that covers all internal bone surfaces (including spicules of spongy bone), and extends into Haversian and Volkmann’s canals. In non-active regions, these cells are squamous-shaped and include osteoprogenitor cells. In areas of active bone deposition, cuboidal osteoblasts are present; areas of bone resorption are marked by the presence of osteoclasts.

The endosteum consists of single layer of bone lining cells that covers all internal bone surfaces (including spicules of spongy bone), and extends into Haversian and Volkmann’s canals. In non-active regions, these cells are squamous-shaped and include osteoprogenitor cells. In areas of active bone deposition, cuboidal osteoblasts are present; areas of bone resorption are marked by the presence of osteoclasts.

In non-active regions of both periosteum and endosteum, bone lining cells are most prevalent (left panel). These cells also include osteoprogenitor cells. In areas of active bone deposition (center panel), cuboidal osteoblasts are present; areas of bone resorption (right panel) are marked by the presence of osteoclasts (arrows).