Currently, a significant proportion of all lesions of the human nervous system is trauma. And only a small part of the lesions directly cause central nervous system diseases.
Due to some of its features, the nervous system is very interesting from the point of view of science. The thing is that the anatomy of the central nervous system is extremely difficult to understand. The nerve fibers that make up its base have their own structure, distinct from other tissues of the human body.
One of the main features of nerve tissue is its extremely low ability to regenerate. This is not to say that damaged nerves are not restored, but their recovery is very slow and requires certain conditions.
Another feature of the nervous system, in general, and the central nervous system in particular, is the blood-brain barrier (BBB).
It is no secret that the brain and spinal cord are in a special fluid that is close in composition to physiological saline, but differs from it in the content of various fractions of proteins and trace elements. Cerebrospinal (or cerebrospinal) fluid is formed from blood and lymph under the influence of a special “filter”, the role of which is played by the blood-brain barrier.
Special cells with endothelial contacts prevent the penetration of blood cells into this fluid. Today, scientists have not fully figured out how the filtering ability of the barrier is regulated, but it is reliably known that its throughput changes with a change in the metabolic activity of the brain. In addition, the blood-brain barrier has differences in different parts of the brain, which leads to its different ability to filter liquids (blood and lymph).
Studies have shown that some of the substances penetrate the BBB mainly from the blood vessels, the other part from the vessels of the lymphatic system, and the rest can come from both media at the same speed. Own, unique and unexplored so far, the system of self-regulation of the composition of the cerebrospinal fluid provides the flow of substances in the amount needed for the central nervous system. This happens with the regulation of the volume of the liquid part, the amount and composition of proteins, as well as the composition of the incoming ions (the latter are represented by potassium and sodium).
Why is the blood-brain barrier necessary?
First of all, its action is aimed at creating a relatively isolated environment for the central nervous system, but it also performs a protective function, preventing the penetration of bacteria and viruses into the cerebrospinal fluid from the blood stream or lymph. It is important to understand that in case of violations in the functioning of the BBB, the consequences will be very serious. So, bacteria that have entered the cerebrospinal fluid lead to meningitis, encephalitis, and other inflammatory processes of the meninges and brain tissues.
A number of studies conducted by specialists have demonstrated the ability to affect the throughput of the blood-brain barrier with various drugs. In addition, previously used drugs began to reveal this feature. Today, doctors are well aware of what medications and how they affect the BBB. Moreover, we have learned to use these properties for the benefit of man.
Thus, the blood-brain barrier performs a number of very significant functions that support the optimal state of the internal organs of the human body. However, it is worthwhile to understand that such features of the barrier make it very sensitive both to injuries and to various pathological conditions, which is why it is so important to understand and consider these aspects in the prevention and treatment of diseases.