osteoclast


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Related to osteoclast: calcitonin, osteoclast activating factor

osteoclast

 [os´te-o-klast″]
1. a large, multinuclear cell frequently associated with resorption of bone.
2. a surgical instrument used for osteoclasis. adj., adj osteoclas´tic.

os·te·o·clast

(os'tē-ō-klast'),
1. A large multinucleated cell, possibly of monocytic origin, with abundant acidophilic cytoplasm, functioning in the absorption and removal of osseous tissue. Synonym(s): osteophage
2. An instrument used to fracture a bone to correct a deformity.
[osteo- + G. klastos, broken]

osteoclast

/os·teo·clast/ (os´te-o-klast″)
1. a large multinuclear cell associated with absorption and removal of bone.
2. an instrument used for osteoclasis.osteoclas´tic

osteoclast

(ŏs′tē-ə-klăst′)
n.
1. A large multinucleate cell found in growing bone that resorbs bony tissue, as in the formation of canals and cavities.
2. An instrument used in surgical osteoclasis.

os′te·o·clas′tic adj.

osteoclast

[os′tē·əklast′]
Etymology: Gk, osteon + klasis, breaking
1 also called osteophage. a large type of multinucleated bone cell with a large amount of acidophilic cytoplasm that functions to absorb and remove osseous tissue. During bone healing of fractures, or during certain disease processes, osteoclasts excavate passages through the surrounding tissue by enzymatic action. Osteoclasts become activated in the presence of parathyroid hormone and also in a lymphokine substance produced by lymphocytes in such diseases as multiple myeloma and malignant lymphomas. See also ossification.
2 a surgical instrument used in the fracturing or refracturing of bones for therapeutic purposes, such as correction of a deformity.
enlarge picture
Osteoclast in bone marrow

osteoclast

A cell responsible for reabsorption of bone matrix, which has a central role in bone remodeling.
 
Morphology
Very large (±100 µm in diameter). It has multiple, relatively uniform, but widely separated round or ovoid nuclei with one or more nucleoli, dense chromatin, abundant blue or purple to pale-pink cytoplasm with many fine red-purple granules.

Origin
Osteoclasts derive from monocyte/macrophage precursors and are unrelated to osteoblasts. Their physiologyic role of bone resorption is linked to charge-coupled proton pumps that secrete acid into the extracellular space.

os·te·o·clast

(os'tē-ō-klast)
1. A large multinucleated cell, possibly of monocytic origin, with abundant acidophilic cytoplasm, functioning in the absorption and removal of osseous tissue.
Synonym(s): osteophage.
2. An instrument used to fracture a bone to correct a deformity.
[osteo- + G. klastos, broken]

osteoclast

1. A giant cell containing many nuclei and capable of bone destruction and absorption. Osteoclasts work in conjunction with OSTEOBLASTS in the process of normal bone growth and in bone repair after fractures.
2. A surgical instrument used to fracture bone.

osteoclast

  1. a multinucleate ameoboid cell that breaks down bone during growth and remodelling.
  2. (also called Chomdrioclast) same kind that breaks down cartilage in the transformation to bone.

Osteoclast

Cell that absorbs bone.
Mentioned in: Multiple Myeloma

osteoclast

large multinucleate cell that absorbs and removes osseous tissue

os·te·o·clast

(os'tē-ō-klast)
1. Large multinucleated cell, with abundant acidophilic cytoplasm, functioning in absorption and removal of osseous tissue.
2. An instrument used to fracture bone to correct a deformity.

osteoclast (os´tēōklast),

n a large, multinucleated giant cell associated with the resorption of bone; the nuclei resemble the nuclei of the osteoblasts and osteocytes; the cytoplasm is often foamy, and the cell frequently has branching processes. They may arise from stromal cells of the bone marrow. They may represent fused osteoblasts or may include fused osteocytes liberated from resorbing bone. They are usually found in close relationship to the resorption of bone and frequently lie in areas of resorption (Howship's lacunae).

osteoclast

1. a large, multinuclear cell frequently associated with resorption of bone.
2. a surgical instrument used for osteoclasis.

osteoclast-activating factor (OAF)
a product of activated T lymphocytes that takes part in local resorption of bone.
References in periodicals archive ?
identification of multiple osteoclast precursor populations in murine bone marrow.
RANKL binds to the RANK receptors on the osteoclast precursors and causes their maturation and activation.
In addition, the proteins needed for the differentiation of the macrophages into osteoclasts will be incorporated in these NPs.
The expression of osteoprotegerin and RANK ligand and the support of osteoclast formation by stromal-osteoblast lineage cells is developmentally regulated.
A receiver operating characteristic (ROC) analysis was calculated to obtain sensitivity and specificity for the mean osteoclast number and a ROC curve has been computed to gain the optimal cut-off value.
Bafilomycin which is not selective for any particular type of vacuolar H+ATPase inhibited bone resorption in osteoclast cultures (48).
Bone resorption by osteoclasts involves the breakdown of both the mineral and organic bone matrix of bone, the latter mainly involving type I collagen.
10,11] Testosterone stimulates osteoblasts, inhibits the apoptosis of both osteoblasts and osteoclasts, and is a precursor of estrogen via aromatization; its net effect is to stimulate bone formation.
In the in vitro study, a mixed culture of osteoblasts and osteoclasts was used to represent the composition of a normal bone and levels of alkaline phosphatase (ALP), a marker of osteoblast activity, were measured.
Without guidance from their osteoclast partners, osteoblasts may lay down bone in uncoordinated ways that create thicker, but less flexible bone.
These medicines work by inhibiting the osteoclast cells that remove bone, thereby preserving bone," explains Levy.
Bisphosphonates prevent bone loss by binding to active sites of bone remodeling, inhibiting osteoclast-mediated bone resorption and eventually causing osteoclast apoptosis.