Osteocyte

Osteocyte

An Osteocyte is a type of bone cell that makes up about 95% of the total bone cell population in the human body. They are derived from osteoblasts, or bone-forming cells, and are essentially osteoblasts surrounded by bone matrix. Osteocytes have a stellate shape, approximately 7 micrometers deep and wide by 15 micrometers in length. They are commonly found in mature bone and are involved in the maintenance of bone tissue.

Structure

Osteocytes are located inside spaces called lacunae found between the concentric layers of lamellae of compact bone. They have long cytoplasmic extensions that reach out to meet the extensions of other osteocytes in tiny channels called canaliculi. These canaliculi form a network for the exchange of nutrients and waste materials.

Function

Osteocytes are the main cells in bony tissue responsible for the maintenance and monitoring of the bony matrix. They are also thought to be involved in the process of bone remodeling by controlling the activity of osteoblasts and osteoclasts. Osteocytes can sense mechanical strain on the bone and can secrete growth factors such as IGF-1 to stimulate bone growth.

Clinical significance

Osteocytes play a crucial role in bone health and disease. They are involved in the pathogenesis of osteoporosis, a condition characterized by decreased bone mass and increased risk of fractures. Osteocyte death is also a key factor in the development of osteonecrosis, a condition that results in the death of bone tissue due to lack of blood supply.

See also

• Bone tissue
• Osteoblast
• Osteoclast
• Osteoporosis
• Osteonecrosis

References

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  Transverse section of bone
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  Bone cells - Osteocytes
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  An osteocyte in rat bone exposed by resin cast etching
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  Osteocyte