GENERAL HISTOLOGY

Detailed explanation-1: -About 90% of the organic component of the bone matrix is due to the type I collagen that is secreted by the osteoblasts and osteocytes. The ground substance is the nonfibrillar organic component of the bone matrix and it fills the space around the collagen fibrils and hydroxyapatite crystals.

Detailed explanation-2: -Osteoblasts are the cells that synthesize bone matrix proteins and are active in bone matrix mineralization. Bone matrix (also known as osteoid) consists of about 33% organic matter (mostly Type I collagen) and 67% inorganic matter (calcium phosphate, mostly hydroxyapatite crystals).

Detailed explanation-3: -Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae. Small channels (canaliculi) radiate from the lacunae to the osteonic (haversian) canal to provide passageways through the hard matrix.

Detailed explanation-4: -Osteoblasts are cells responsible for the secretion and deposition of bone morphogenetic proteins (BMPs) into the extracellular matrix during bone formation.

Detailed explanation-5: -Osteocytes have been shown to synthesize new bone matrix at the surface of the lacunae, and there is evidence for their ability to resorb calcied bone from the same surface [178].