How many layers make up bone?

Bone tissue can be divided into two types: cortical (or compact) bone and cancellous (or spongy) bone.

Each one is composed of different layers:

- Cortical bone is more dense and makes up the outer layer of bone. It is composed of three layers: the outer circumferential lamellae, the inner circumferential lamellae, and the interstitial lamellae.

- Cancellous bone is found inside cortical bone. It is made up of a network of trabeculae, which are thin rods of bone tissue. The trabeculae are arranged in a way that maximizes strength and minimizes weight. Cancellous bone contains three types of lamellae: trabecular lamellae, peritrabecular lamellae, and endocortical lamellae.