Neurons would be unable to carry out their functions if it were not for the glial cells present throughout the tissue of our nervous system. Glial cells are part of the information transmission process, which is why this type of cells are essential for the proper functioning of both the central and peripheral nervous system.
There is a variety of glial cells present in our body, some of them are: astrocytes, oligodendrocytes, ependymal cells, Schwann cells, etc.
If you want to know more about what glial cells are, their function and their types , we invite you to continue reading this article where you will learn about the concept, characteristics and each type of glial cell, as well as its function.
What are glial cells
Glial cells are also known simply as “glia”, whose meaning comes from the Byzantine Greek, which means league, union or glue. So, based on what was described above, we ask ourselves, what are glia cells, since we can say that they are the entire group of cells that are part of the tissue of our nervous system . Its main role is to maintain a suitable environment for the proper functioning of neurons.
There are various types of glial cells, which is why it was necessary to create a classification that could be according to:
Its location: central nervous system or peripheral nervous system.
On the other hand, something interesting related to glial cells is that, before it was believed that mental problems such as schizophrenia or bipolarity were due to functional irregularities of neurons, however, the functional discovery of glia contemplated a new field of study for researchers.
Characteristics of glial cells
- The group of glial cells is called neuroglia.
- They are structural support cells .
- They are more numerous, smaller, and morphologically and functionally different from neuronal cells .
- They do not have axons, dendrites or nerve tubes.
- They derive from the layer of embryonic tissue called neuroectoderm, with the exception of microglia that derive from the mesoderm.
- They have essential functions for the normal development of neurons.
- They play a fundamental role during neuronal communication .
- They do not have the ability to send electrical impulses.
- The number of glial cells can vary depending on the complexity of the organism, the value always increases exponentially.
The millions of neurons present in our brain develop properly thanks to the fact that glial cells provide them with support, union and structure, becoming practically essential for the nervous mechanics of our body. In this article you will learn about the Neuron: what it is, types, parts and functions .
Glial cell function
Glial cells and neurons are totally different structures, however, both have a functional dependence for our nervous system to work correctly. Below we will detail the functions that glial cells perform in our body:
- Oligodendrocytes: their main function is to form the myelin layer of the Central Nervous System.
- Astrocytes: serve as structural support for neurons, supply nutrients to neurons, capture chemical transmitters, repair and regenerate throughout their life.
- Microglia: protect our brain from any invading microorganism, they proliferate rapidly when there is inflammation or injury to nervous tissue.
- Ependymal cells: they form the cerebrospinal fluid, the movement of their cilia influences the direction of cerebrospinal flow, the so-called tanycytes play a fundamental role in the transport of hormones in the brain.
- Schwann cells (neurolemocyte): provide the myelin layer responsible for protecting the neurons of the Peripheral Nervous System.
- Satellite cells: serve as support, protection and nutrition for the cranial, spinal and automatic nerve ganglia in the PNS.
Here you can watch a video, where you can expand information about glial cells and their functions.
Types of glial cells
Glia of the central nervous system:
- Oligodendrocytes: are the cells that form the myelin sheath. The myelin sheath is an insulating layer that covers some of the neuronal axons.
- Astrocytes: it is the most abundant glial cell and is characterized by having a stellate shape. We can find them in the spinal cord and the brain, forming the blood-brain barrier.
- Microglia: as their name indicates, these cells are the smallest in the central nervous system. Some researchers believe it is a type of white blood cell that protects against foreign matter.
- Ependymal cells: They have a ciliated shape and are found surrounding the capillaries of the choroid plexus. They are structured by forming the epithelial lining of the central canal of the spinal cord and the ventricles of the brain.
Glia of the peripheral nervous system:
- Schwann cells (neurolemocyte): they are the equivalent of oligodendrocytes in the CNS, so they perform similar functions.
- Satellite cells: they are structural, protective and nutritional cells for ganglion neurons.