Bone Structure

Cancellous bone is "spongy bone." It is composed of tiny "spicules" of bone oriented in various directions which give it a spongy appearance grossly. It is very light but strong.

Compact bone is very heavy, dense, strong bone. It is found where strength is more important than lightness.

Bone forming cells are called osteoblasts. They produce the bone matrix which, when it becomes ossified, traps the cells, which are then called osteocytes. The osteocytes are in contact with one another, and their blood supply, through cellular processes in tiny channels (canaliculi) in the bone matrix. Osteoclasts are bone-removing cells.

Haversian systems are the tiny laminated cylinders that make up compact bone. At the center of each Haversian system is the Haversian canal that contains blood & lymph vessels and nerves.

 Blood supply to bone

Volkmann's canals bring many tiny blood vessels in from the periosteum to the blood vessels in the Haversian canals.

Nutrient foramina bring large blood vessels into and out of the bone marrow.