Osteoclasts have all of the following except -
Ans. is 'b' i.e., Receptor for parathormone o Osteoclasts are found in sites in which bone is being remodeled. These are multinucleated giant cells and formed by fusion of mononuclear cells (monocytes & macrophages). These cells are the principal mediator of bone resorption.The characteristic feature is the area of infolded plasma membrane known as ruffled border which is surrounded by an organelle free clear zone through which osteoclast attaches to bone & which is the site of bone resorption.# Though osteoclasts are responsible for resorption, they act when they are activated through osteoblasts# This is because, receptors for hormone that stimulate resorption (parathormone) are present on osteoblasts (not on osteoclasts).# Parathormone activates osteoblasts which then secrete mediators of osteoclastogenesis that stimulate osteoclasts for bone resorption.# RANK binds to RANK Ligand which stimulates bone resorption.
Bone resorption
Receptor for parathormone
Ruffled border
Rank ligand
General