PERIOSTEUM E ENDOSTEUM
As mentioned at the beginning of this module, with rare exceptions, every bone surface is lined by cells. These cells can be of three types: osteoprogenitor cells (bone tissue stem cells), osteoblasts, or osteoclasts. Osteoblasts constitute the majority of the cells lining
the anterior surface, and together they constitute a layer called the endosteum (highlighted in light blue).
The endosteum is generally a very thin layer, often formed by a layer of cells arranged over the bone matrix.
See on the next page that the endosteum lines not only the large bone cavities (e.g., the medullary canals), but also all the small cavities located between the trabeculae of the cancellous bone and even the inner wall of the Haversian canals.
Osteocytes are highlighted in green.
the anterior surface, and together they constitute a layer called the endosteum (highlighted in light blue).
The endosteum is generally a very thin layer, often formed by a layer of cells arranged over the bone matrix.
See on the next page that the endosteum lines not only the large bone cavities (e.g., the medullary canals), but also all the small cavities located between the trabeculae of the cancellous bone and even the inner wall of the Haversian canals.
Osteocytes are highlighted in green.
