GENERAL HISTOLOGY

Detailed explanation-1: -The outer layer of a bone is called compact or cortical bone. This layer is hard and particularly solid, and it makes sure that our bones can withstand daily physical strains. The outer layer has a thin coating called the periosteum.

Detailed explanation-2: -Compact bone is the solid, hard outside part of the bone. It looks like ivory and is extremely strong. Holes and channels run through it, carrying blood vessels and nerves. Cancellous (KAN-suh-lus) bone, which looks like a sponge, is inside compact bone.

Detailed explanation-3: -Spongy (cancellous) bone is lighter and less dense than compact bone. Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. The canaliculi connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply.