The human body is made up of many cells. All of them have different structures and perform different functions. But there is something that unites all their diversity - this is an ongoing process of updating. It can be considered as an example of bone structures. Osteoclast cells and osteoblasts are similar to asphalt paving teams: some remove old asphalt, others lay new. Bone tissue is continuously updated, and the brain controls this work.
When a malfunction occurs, there is always a reason: either the brain gave the wrong command, or there wasn’t enough building material, or osteoblasts (cells building tissue) decreased in number. And osteoclasts (destroyers) remained the same. This leads to various diseases, in particular, osteoporosis.
How is bone tissue
Bone is an organ of the body that is constantly being updated. It consists of several types of tissue, the most important of which is bone. In the developed intercellular substance of the bone, rich in salts, three types of cells work:
- Osteocytes.
- Osteoblasts.
- Osteoclasts.
Briefly described, these are guardians, creators and destroyers.
Osteoblasts
The name of these cells comes from the ancient Greek words “bone” and “sprout”. These are young cells that form bone tissue. First they create a matrix, a network of intercellular substance. After this stage, osteoblasts produce matrix calcification, turning themselves into osteocytes.
Osteoblasts have a cubic or pyramidal shape. They have developed a granular endoplasmic reticulum that synthesizes proteins. The Golgi complex leads them to a bone under construction. Mitochondria provide normal cell activity, providing it with energy. Osteoblasts may share mitosis.
The main task of osteoblasts is the formation of matrix proteins, which include collagen, osteocalcin and osteopontin. After their synthesis, the deposition in the matrix of mineral substances begins. They also secrete ossein, which sticks together calcium salts. As a result, the bone becomes a mineral-organic structure.
Osteoblasts help transport calcium and phosphate, which helps in alkalizing the body. When bone is formed, they are located on the entire surface of the bone beams, and after - in places of destruction and regeneration after injury, as well as in the periosteum.
Osteocytes
An osteocyte is called a mature bone cell. This is a definitive cell, that is, it has come to its final form. She does not have the ability to share through mitosis. When the matrix structure is completely filled with mineral matter, the osteoblast stops working and the cell becomes an osteocyte. The function of osteocytes is to ensure the maintenance and regeneration of bones, as well as the regulation of mineral composition.
In the bone structure there are gaps in which osteocytes are located. In the process of wiring, osteoblasts create long processes of osteocytes that are in contact with each other by nexuses. The processes located near the vessel receive nutrition and oxygen from it. The number of such processes can be very large, up to several hundred. The osteocyte is star-shaped due to the many processes that are located in the bone tubules. After aging and apoptosis (self-destruction), the tubules empty.
Osteoclast cells
Osteoclasts are giant (40 μm in diameter) multinucleated cells. They destroy bone by dissolving mineral salts and destroying the collagen matrix. They have several nuclei (from 5 to 20), many Golgi complexes, mitochondria, and lysosomes. Enzymes are released from lysosomes that initiate bone resorption.
In other words, osteoclast is a bone macrophage. It approaches the bone, attaches to it with a corrugated border and forms a membrane that protects the osteoclast environment from the action of hormones. Then it produces an acidic medium that dissolves mineral salts. After using the enzymes lysosomes, the old cells are digested. Part of the substance goes into the bloodstream, the rest is used to support the process of bone destruction.
Work in tandem
Osteoclasts work as a group. They eat into the old bone and tunnel it. The daily passage of such a group is 50 microns. After the passage of the first group, the second movement begins, consisting of osteoblasts. They are located on the walls of the tunnel and fill their surface. After that, they begin to synthesize the matrix at a rate of 1 μm per day. At the same time, capillaries begin to sprout along the axis of the tunnel.
Having built a matrix, osteoblasts begin to become walled up, creating a mineral-protein structure around them. Upon reaching the goal, when the bone is already built, osteocytes remain in the gaps. They live for a while, after which they end their lives with self-destruction (apoptosis).
The process of working in tandem of two types of bone cells is called remodeling. It is regulated by hormones of parathyroid glands that activate osteoclasts. It is a parathyroid hormone. The thyroid gland produces calcitonin, which stimulates bone formation. In addition to these, many other hormones that produce the sex glands, the pituitary and the pancreas are involved in remodeling.
In case of hormones malfunctioning, there may be a lack of osteoblasts or their inhibition. Together with the activity of osteoclasts, this can lead to disease. For example, osteoporosis and its consequences: fractures and damage to joints.
Conclusion
For life, the proper functioning of all parts of the body, even such small structures as osteoclasts, is necessary. This allows all organs of the human body, from the thyroid gland to the bones, to interact with each other. That is why knowledge about a healthy lifestyle, proper nutrition and maintaining health is needed. Then premature osteoporosis will not be scary.