Types of Bone Cells Found in Bone Tissue

Bones as you know is very important and vital structure of human body, which not only gives support to human body but, also helps in its movements and also help in protecting vital organs of human body from various kinds of injuries. Now, as every tissue is made up of different kind of cells and extracellular matrix, in the same way, bone being a tissue is also made up of various kinds of cells and also contains a unique extracellular matrix. Four different types of cells are found in bone tissue. These four different types of bone cells found in bone tissue are-

1.      Osteogenic cells.
2.      Osteoblast cells.
3.      Osteocytes.
4.      Osteoclasts.
 

1.      Osteogenic cells-

Now, first type of bone cells which is found in bone tissue is osteogenic cells, which are also one of the unspecialized stem cells that mean undifferentiated stem cells. Osteogenic cells are derived from mesenchyme.

Osteogenic cells are only bone cells out there out of four different types of bone cells which undergo cell division. New cells which are formed from the cell division of osteogenic cells are known as osteoblasts. Yes, you got it right, osteogenic cells are the bone cells which develop into osteoblasts after cell division of osteogenic cells. Now, where are these osteogenic cells found in bone tissue? These osteogenic cells are found in endosteum of bone, in canals found in bone tissue which contain blood vessels and also it is found along inner portion of periosteum of bone. So, yes, you get it right, osteogenic cells are very important type of bone cells out of other four types of bone cells. They are the only cells from which next type of bone cells that means, second type of bone cells, that is, osteoblast cells develop after cell division. Osteogenic cells are the only cells which undergo cell division.

2.      Osteoblast cells-
Osteoblasts, as already told above in this article, are the second type of bone cells, which develop from osteogenic cells after cell division. Osteoblast cells are also known as bone building cells as they perform the function of formation of bone tissue extracellular matrix synthesis. Osteoblasts are the only type of bone tissue cells which form bone tissue extracellular matrix by synthesizing and secreting various collagen fibers and other organic components needed or required to build or you can say to form extracellular matrix of bone and these organic components and collagen fibers secreted and synthesized by osteoblasts further initiate calcification of bone tissue.

3.      Osteocytes-
Now, third type of bone cells found in bones is osteocytes. Osteocytes maintain bone tissue just like osteoblasts perform the function of formation of bone tissue extracellular matrix; osteocytes perform the function of bone tissue maintenance. Osteocytes are also known as mature bone cells, which develop from osteoblasts. Osteoblasts surround themselves with extracellular matrix and when they become trapped in their secretions, they are then known as osteocytes, which is the third type of bone tissue cells. Osteocytes, as I have already told you above, that, they perform the function of maintenance of bone tissue. They maintain daily metabolism of bone routinely. It absorbs various nutrients from blood and eliminates various wastes in blood from bone. Osteocytes are just like mini digestive system of bone tissue which perform the function of absorption of various nutrients from blood and elimination of wastes into blood, just like digestive system of human body which absorbs various nutrients from food and eliminate waste through kidney.

4.      Osteoclasts-
Now, osteoclasts which is not only the fourth type of bone tissue cells, but also the last type of bone tissue cells which develop from or you can say are derived from fusion of as many as fifty monocytes. Osteoclasts are huge in size as compared to size of other three types of bone tissue cells that is why they are also known as huge bone cells. Now, where are they found in bone tissue? They are found in endosteum of bone and one more identification sign of osteoclasts along with being huge in size as compared to other three types of bone cells, is its ruffled border, which is formed by plasma membrane on side of cell which faces the bone surface, the plasma membrane on this side of cell is deeply folded which is known as ruffled border. From this ruffled border, osteoclasts release their lysosomal enzymes and its various acids which digest the bone protein and bone minerals of underlying bone extracellular matrix. This process of breakdown of bone extracellular matrix by digesting or in other words breaking its proteins and minerals components is known as resorption. Osteoclasts also help in maintaining normal blood calcium level when required and in response to certain specific hormones.

So this was all about various or different types of bone cells found in bone tissue which forms an important part of human body.

Do you know- What are Different Causes of Rickets?