EVERYDAY SCIENCE

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 heaviest, hardest type of bone. It needs to be very strong as it supports your body and muscles as you walk, run, and move throughout the day. About 80% of the bone in your body is compact. It makes up the outer layer of the bone and also helps protect the more fragile layers inside.

Detailed explanation-3: -Compact bone is the denser, stronger of the two types of osseous tissue (Figure 6.3. 6). It makes up the outer cortex of all bones and is in immediate contact with the periosteum. In long bones, as you move from the outer cortical compact bone to the inner medullary cavity, the bone transitions to spongy bone.

Detailed explanation-4: -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-5: -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.