Endosteum

As endosteum ( endosteum ) is called the inner periosteum. In contrast to the outer periosteum ( periosteal ) the endosteum is inside the bone and coats the surfaces of the trabeculae and the marrow cavity.

The endosteum is a single layer of connective tissue cells and underlain by a thin layer of collagenous and reticular fibers. It contains connective tissue stem cells ( mesenchymal cells ) that can differentiate into osteoblasts, fibroblasts and, if necessary. The bone resorbing osteoclasts originate from hematopoietic stem cells and spread via the blood to the endosteum. These cells play an important role in bone remodeling ( remodeling ) and in bone healing.