Cerebrospinal Fluid: Composition, Functions And Disorders
It is popular knowledge that the brain is located inside the skull, being protected, among other things, by it and by different membranes, such as the meninges.
The correct functioning and protection of this organ is essential for survival, so it is necessary to nourish it and avoid possible damage, such as that caused by blows or intracranial pressure. Furthermore, in its necessarily continuous operation, waste is generated, which can be harmful and therefore must be removed from the system.
A very important liquid that circulates through the nervous system participates in all of this, known as cerebrospinal fluid
Cerebrospinal or cerebrospinal fluid is a substance present in the nervous system, both at the level of the brain and spinal cord which performs various functions such as protection, maintenance of intracranial pressure and health of the thinking organ.
Its presence in the nervous system occurs especially in the subarachnoid space (between the arachnoid and the pia mater, two of the meninges that protect the brain) and the cerebral ventricles. It is a transparent liquid of fundamental importance in the conservation and good health of the brain, with a composition similar to that of blood plasma, from which it is derived. Despite being colorless, different alterations and infections can give it different shades, its color being a sign of the presence of a problem.
Cerebrospinal fluid life cycle
The cerebrospinal fluid is synthesized in the choroid plexuses, small structures present in the lateral ventricles, the main function of these plexuses being the production of this substance. This production occurs continuously, being renewed to maintain a constant amount of said substance
Once emitted, it flows from the lateral ventricles to the third ventricle and subsequently to the fourth through the Sylvian aqueduct. From there it ends up projecting into the subarachnoid space through an orifice known as the orifice of Magendie and the orifices of Luschka, openings located in the fourth cerebral ventricle that bring the ventricular and meningeal systems into contact when communicating with the cisterna magna of the subarachnoid space ( located between the arachnoid meninges and pia mater). From that point it circulates through the meninges throughout the entire nervous system, performing various functions in the process.
To complete its life cycle, it is finally reabsorbed through the arachnoid granulations, which connect with the veins present in the dura mater, so the liquid ends up reaching the bloodstream.
The average life cycle of this substance is around three hours between its secretion, circulation, collection and renewal.
Composition
As just mentioned, The composition of cerebrospinal fluid is very similar to that of blood plasma the main variations being the comparatively much lower presence of proteins (it is estimated that in blood plasma the presence of proteins is two hundred times greater) and the type of electrolytes that are part of it.
A water-based solution, cerebrospinal fluid has various components of great importance for the maintenance of the nervous system, such as vitamins (especially group B), electrolytes, leukocytes, amino acids, choline and nucleic acid.
Within this large number of elements, In the cerebrospinal fluid, the presence of albumin stands out as the main protein component, along with others such as prealbumin, alpha-2-macroglobulin or transferrin. Apart from these components, the high presence of glucose stands out, having around 50 to 80% presence in this solution that is so vital for the brain.
Principal functions
We have visualized an overview of what cerebrospinal fluid is, where it circulates and what it is composed of. However One may wonder why this substance is so important for the correct functioning of the nervous system as a whole. To answer this question it is necessary to see what functions it has.
One of the main functions of the cerebrospinal fluid is to be the main mechanism for eliminating waste produced by the continuous functioning of the nervous system, residues that could seriously affect its operation. Thus, the circulation of cerebrospinal fluid carries away these substances and metabolites, which will end up being excreted from the system. If this substance did not exist, the toxins and leftover particles would become sedimented in regions of the nervous system and adjacent areas, so that many problems would appear in the state of the living cells: they would neither be able to free themselves from these leftover elements, nor would they be able to access them. to the parts of these that can be recycled once they have passed through the appropriate place.
Another of the most important functions of the cerebrospinal fluid is to keep the brain nourished, as well as to ensure the constancy of the environment between the different cells of the brain and the spinal cord. It is a kind of chemical “buffer” that allows the room for maneuver to increase in case certain hormonal imbalances appear, e.g. and when there are homeostasis problems in general
The cerebrospinal fluid also allows the brain to float within the skull, greatly reducing its weight. This flotation also serves as cushioning against attacks, blows and movements by reducing the possibility of impact against the bones of the skull or external elements.
Likewise, the cerebrospinal fluid has to do largely with the maintenance of intracranial pressure making it neither too big nor too small, maintaining a constant balance that allows correct functioning.
Finally, it also participates by acting as an immune system, protecting the nervous system from harmful agents. It also contributes as a means of transporting hormones.
Derived disorders
Thus, the nervous system has an essential tool in the cerebrospinal fluid to function correctly.
However, It is possible that alterations may occur in the synthesis, circulation or reabsorption of this substance which can cause different problems, two of them being the following.
1. Hydrocephalus
This concept refers to the excessive presence of cerebrospinal fluid, there being such an accumulation that pressure of the brain against the skull is caused. Some of the elements that can cause it are tumors, infections or trauma, but it is also common to find congenital hydrocephalus, that is, present from birth.
It can cause headaches, vomiting, cognitive or coordination impairment or double vision, among other symptoms. In the case of congenital hydrocephalus, it is the reason for severe difficulty in development and intellectual deficit. It is generally due to obstructions in the circuit, a common example being a clogged foramen of Magendie. To treat these problems, it is possible to perform surgery to create an escape route for the fluid to other areas, such as the stomach.
2. Intracranial Hypertension/Hypotension
An excess or deficit of cerebrospinal fluid can cause the pressure on the brain inside the skull to be excessive or too low to allow proper functioning. While hypotension would occur due to the loss or little production of cerebrospinal fluid, hypertension would occur due to an excess of this, which can be serious because it puts pressure on areas of the nervous system and prevents them from functioning well (or even kills areas of cellular tissue). ).
In any case, the alterations in the cerebrospinal fluid that may appear in these cases add to the problems of the heart condition that causes, so the danger increases. It is necessary to treat both groups of symptoms to avoid a chain effect resulting from problems in the functioning of the nervous system and the circulatory system.
