EVERYDAY SCIENCE

Detailed explanation-1: -Osteoclastogenesis. Osteoclasts, the cells devoted to resorb the bone matrix, arise from the monocyte/macrophage lineage (34). They are multinucleated cells (from four up to twenty nuclei) formed by the fusion of mononuclear precursors (35).

Detailed explanation-2: -Osteoclasts Resorb Bone The area of the osteoclast next to bone forms a “ruffled border” consisting of multiple infoldings of the osteoclast cell membrane. It secretes acid and proteases across the ruffled border, and these dissolve the mineral of bone and destroy the organic matrix (see Figure 9.8.

Detailed explanation-3: -Osteoclasts dissolve bone mineral by massive acid secretion and secrete specialized proteinases that degrade the organic matrix, mainly type I collagen, in this acidic milieu.

Detailed explanation-4: -Osteoclasts, the cells that break down and reabsorb bone, stem from monocytes and macrophages rather than osteogenic cells.. There is a continual balance between osteoblasts generating new bone and osteoclasts breaking down bone.

Detailed explanation-5: -The osteoclasts are the mediators of the continuous destruction of bone. Osteoclasts occupy small depressions on the bone’s surface, called Howship lacunae; the lacunae are thought to be caused by erosion of the bone by the osteoclasts’ enzymes.