Ependymal cells: types and functions in the body

This type of glial cell allows cerebrospinal fluid to circulate in our body.

The functioning of the nervous system depends on a large number of specialized cells that, inside or outside the brain, are responsible for working together with the rest of the organism to keep it functioning. Ependymal cells are one of the elements that play a key role in this..

Below we will see what ependymal cells are and how they are related to the activity of the brain and the nervous system in general.

Ependymal cells: definition

Ependymal cells are a type of epithelial cells associated with the body cavities through which the cerebrospinal fluid circulates. They are also part of the glial cells, which share space with neurons in the nervous system, although their function is not to transmit signals at full speed.

Thus, ependymal cells are part of a larger family of microscopic elements whose components include, for example, microglia or astrocytes, all of which are representatives of the neuroglia..

What is their function?

It is currently believed that the main functions of ependymal cells are twofold.

On the one hand, when they join together, they create the membranes that the cerebrospinal fluid circulating through the ependymal canal of the spinal cord (a kind of duct that runs through the spinal cord). (a kind of duct that runs along the spinal column) and the ventricles of the brain, preventing it from spilling into other tissues and passing to areas of the body where it should not be. In other words, they coat the circulation spaces with this substance.

On the other hand, it is believed that the ependymal cells make possible the creation of the cerebrospinal fluid itself, as we shall see. This is very important, because although the latter is a substance relatively poor in a variety of valuable cellular contents (compared to blood), it allows the entire nervous system to function well and to have extra protection against possible incidents.

What is cerebrospinal fluid?

To fully understand the role that ependymal cells play in our body, it is necessary to understand why there is cerebrospinal fluid circulating in our nervous system. The cerebrospinal fluid has the following functions:

1. it cushions

This substance forms a kind of liquid cushion that directly protects many of the areas of the nervous system (which, let us remember, is full of fragile and delicate parts) from shocks. By leaving a space between tissues in which there is a water-like substance, the deformation caused by impacts does not worsen the condition of other areas so much.It acts as a firewall.

2. It serves to regulate the levels of substances.

This fluid creates a medium in which various components that are rejected or needed by the body's cells are expelled and taken up. Thus, they contribute to maintaining the balance of proper functioning, contribute to maintain the balance of the correct functioning of the organism..

3. It allows the uptake of useful materials for the cells

In the cerebrospinal fluid it is possible to find elements that the cells can use as raw material to maintain their functioning, repair themselves, grow, etc.

4. It shapes the nervous system

The presence of ventricles with fluid in them forms a kind of "soft" skeleton. a sort of "soft" skeleton that gives shape to this structure of the nervous system and allows it to be maintained in more or less the same arrangement at all times.

Types of ependymal cells

There are three types of ependymal cells, each with its own characteristics, location in the nervous system and way of functioning. These are the tannocytes, ependymal cells and choroidal epithelial cells..

6. Tannicites

The tannocytes are ependymal cells that cover the walls of the third ventricle, deep in the brain, in close proximity to a structure of the nervous system known as the diencephalon.. It is believed that among its main functions is to drive the cerebrospinal fluid thanks to its thin extensions.

7. Ependymal cells

Ependymal cells are the most common and numerous type of ependymal cell, as they are present both in the ependymal canal and in the cerebrospinal canal. are present both in the ependymal canal and in the ventricles of the brain.. Its function is very basic: to create a relatively insulating barrier so that certain components do not pass from one side to the other, like a microscopic membrane.

8. Choroidal epithelial cells

Choroidal epithelial cells, finally, form the type of ependymal cell that is responsible for forming the choroid plexuses, the sites where cerebrospinal fluid is produced, as well as for creating a protective and insulating barrier.

9. Disorders

Certain alterations in these cells and in the tissues they form can lead to the development of disorders which, in certain cases, threaten the life of the patients.. For example, hydrocephalus, a medical condition in which too much cerebrospinal fluid is generated and the nervous system expands, putting pressure on the bony walls that cover it and damaging itself in the process.

Cranial hypertension or hypotension. would be another example of what can go wrong with this system of nervous system ventricles, because pressure failures can seriously interfere with nerve activity or even lead to death.

An important component of the nervous system

In conclusion, ependymal cells are an example of the extent to which the functioning of the nervous system depends not only on neurons. Surrounding these nerve cells are many others that, working in a coordinated manner, make it possible for the whole to perform its work as it should. In this periphery of Biological processes there is still much to be discovered.