👉 Endosteal, also known as periosteum or periosteoid, is a layer of connective tissue that forms the outer layer of bone. It is located between the primary and secondary ossification centers of the body. Endosteal is composed of two types of cells: osteoblasts (prosthetic cells) and osteoclasts (reinforcing cells). Osteoblasts produce new bone, while osteoclasts break down old bone tissue. The end