Bone cells


Bone tissue contains five basic types of bone cells. There are cells which are responsible for the response of the body to trauma and fracture, and those which secrete the basic chemical compound which bones are made of. There are cells mature bone cells and cells that break down the bone tissue. All bone cells have a particular function and each is needed for bones to retain their strength, develop, heal, and grow.

Cells which are responsible for trauma response are known as osteogenic cells. They can be found in the bone tissue which contacts the endosteum and the periosteum. These cells respond to trauma and begin the healing process immediately by “calling” other cells to action such as the bone forming cells (osteoblasts) and the bone destroying cells (osteoclasts) which collective try to repair the damage. Osteoblasts are cell which secrete basic un-mineralized compound to help in the process of bone repair, bone growth, or bone regrowth. Where the bone tissue has higher metabolism, the osteoblast cells are more plentiful, this includes the border of the medullary cavity and under the periosteum.


A mature osteoblast is known as an osteocyte. While osteocytes are technically a different bone cell altogether, the osteoblast changes into an osteocyte over time. Osteoblasts have the unique ability to secrete bone tissue and form the tissue around itself like a protective wall of bone tissue. They are responsible for the healy maintenance of healthy bone by secreting enzymes and directing the mineral content of the bone.

The cells which are responsible for the breakdown of bone tissue, which releases calcium, are known as osteoclasts. Osteoclasts are larger than most bone cells because they are multi-nuclear and release and enzyme that destroys the bone tissue when necessary. This action releases calcium in the body. Magnesium and other minerals are also released into the blood stream when bone tissue is broken down. Osteoclasts are vital to the process of bone growth, the rebuilding of bone, and the bone’s ability to repair itself. Just like a forest, new growth often requires the devastation of older growth, only with bones the scale is much smaller.


Bone cells
Image: Bone Cells

The cells which create the lining of the bones are derived from the osteoblasts. This lining of cells is found on the surface of most adult bones. These cells primarily are responsible for the regulation of phosphate and calcium through the entire bone matrix. Regulating these minerals keeps the mineral content at a healthy level, avoiding too much or too little nutrient and mineral content throughout the bone structures.


As it has been already covered, the bones of the human body are typically made up of a spongy material that is protected by a hard outer surface. The softer bone tissue dwells deep inside the compact hard bone tissue, which forms a protective layering for the soft tissue. Soft bone tissue is considerably porous and is designed with small spokes of trabeculae which give the soft bone tissue its lace-like appearance. Despite the fact that the soft bone tissue is softer than compact bone tissue, the vascular activity is quite high and its unique design gives bones a considerable boost in strength. Despite its strength, the soft bone tissue does not add considerable weight and is in fact very light in the body’s structure.

The compact bone tissue (hard bone tissue) is remarkably dense and comprised of a very precise network of microscopic cylinders that run along the length of the bone. These structures are known as osteons and are reminiscent of columns that are suitable for bracing the bone structure. Osteons are also known as haversian systems within the bone tissue. The osteon creates a matrix of concentric rings which have been referred to as lamellae. These lamellae create a protective barrier around the haversian canal. The central canal hosts a nerve as well as nearly microscopic nutrient vessels. Nutrients are diffused and placed to use within the bone structure through canaliculi, which are the basic connective system associated with the lacunae. The lacunae live structurally between the lamellae in an organized and even fashion. This system creates optimal position and structure to increase metabolic activity at the osteon level. Within the osteon’s own system, there are partial osteons known as interstitial systems. The osteons are connected to blood vessels and nerves via canal systems within the compact bone tissue.
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