RANKL/RANK/OPG Signaling Pathway | Osteoclast Differentiation

In this video we have discussed the RANKL RANK OPG Signaling Pathway. Osteoclasts are specialized multinucleated giant cells that resorb bone. This is carried out primarily due to remodeling of extracellular matrix. Osteoclasts are found on those surfaces of bone which are undergoing resorption. On such surfaces, the osteoclasts are seen to be located in shallow depressions called resorption bays (Howship's lacunae). The resorption bays are created by erosive action of osteoclasts on the underlying bone. The border of the lower part of an osteoclast exhibits finger-like processes due to presence of deep infoldings of the cell membrane; this border is called ruffled border. The ruffled border lies in contact with the bone surface within a resorption bay. The periphery of the ruffled border is surrounded by a ring-like zone of cytoplasm which is devoid of cell organelles but is rich in actin filaments. This zone is called clear zone or sealing zone.