Ependymal cells: types and functions in the 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 body to keep the functioning of the brain active. same. The ependymal cells are one of the elements that play a key role in this..

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

• Related article: "Parts of the human brain (and functions)"

Ependymal cells: definition

Ependymal cells are known as a type of epithelial cell that is associated with the cavities of the body through which the fluid circulates. cerebrospinal fluid. It is 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 among whose components we find, for example, microglia or astrocytes, all of them representatives of neuroglia.

What is your function?

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

On the one hand, when they come together they create the membranes that maintain cerebrospinal fluid in circulation through the ependymal canal of the spinal cord (a kind of conduit that runs through the spine) and the cerebral ventricles, preventing it from spilling through other tissues and passing into areas of the body where it should not be. In other words, they cover 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 will see. This is very important, because despite the fact that the latter is a relatively poor substance in a variety of valuable content for cells (if we compare it with blood), allows the entire nervous system to function well and has 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 through our nervous system. Cerebrospinal fluid has the following functions:

1. cushions

This substance forms a kind of liquid mattress that directly protects many areas of the nervous system (which, let's remember, is full of fragile and delicate parts) from blows. By leaving a space between tissues in which there is a substance similar to water, the deformation produced by the impacts does not worsen the state of other areas as much: 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 cells of the body are expelled and taken up. So, contribute to maintaining the balance of the proper functioning of the body.

3. Allows us to capture useful materials for cells

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

4. Shapes the nervous system

The presence of ventricles with liquid of another form a kind of "soft" skeleton that gives shape to this structure of the nervous system and allows it to always remain more or less with the same disposition.

ependymal cell types

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

6. tanicitos

Tanycytes are ependymal cells that line the walls of the third ventricle, deep within the brain. very close to a nervous system structure known as the diencephalon. It is believed that one of its main functions is to drive the cerebrospinal fluid thanks to its fine extensions.

• You may be interested in: "Diencephalon: structure and functions of this brain region"

7. ependymocytes

Ependymocytes are the most common and numerous type of ependymal cell, as they are present in both the ependymal canal and the cerebral ventricles. 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 plexuses. choroids, the places where cerebrospinal fluid is produced, as well as creating a protective barrier and insulating.

9. Disorders

Some alterations in these cells and in the tissues they form can cause them to appear disorders that, in certain cases, threaten the lives of patients. For example, the hydrocephalus, a medical condition in which too much cerebrospinal fluid is generated and the nervous system expands, pressing 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 ventricles of the nervous system, 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 does not only depend on neurons. Around these nerve cells there are many others that, working in a coordinated manner, make it possible for the whole to carry out its work as it should. In this periphery of biological processes there are still many things to discover.