MICROANATOMY

Detailed explanation-1: -Bone is specialized connective tissue with a calcified extracellular matrix (bone matrix) and 3 major cell types: the osteoblast, osteocyte, and osteoclast. The first type of bone formed developmentally is primary or woven bone (immature). This immature bone is later replaced by secondary or lamellar bone (mature).

Detailed explanation-2: -Lamellar bone is a secondary bone created by the remodeling of woven bone.

Detailed explanation-3: -Mature lamellar bone exists as cortical (also called compact) or trabecular (cancellous, spongy) bone.

Detailed explanation-4: -A lamellar unit is composed of five sublayers. Each sublayer is an array of aligned mineralized collagen fibrils. The orientations of these arrays differ in each sublayer with respect to both collagen fibril axes and crystal layers, such that a complex rotated plywood-like structure is formed.