On numerous occasions we have talked about the nervous system, the cells that make it up, their functions and what happens when they do not function properly. Now, what makes up the neural cells that inhabit the nervous system?

Throughout this article we will talk about the different parts of the neurons , as well as their main characteristics and the functions that each one of them has and that make possible the transmission of information throughout the entire nervous system.

What is a neuron?

Neurons are small cells that inhabit our nervous system and are responsible for activating or inhibiting the electrical activity of the system. Their main function is to receive electrical stimuli and conduct them to other neurons. This stimulus or electrical reaction is known as action potential.

Therefore, neurons send to each other an infinite amount of action potentials that make possible the functioning of our nervous system, thanks to which we can move our muscles, feel pain or even dream.

It is estimated that, in our brain alone, there are about 86 billion neurons. However, at the time of our birth there may be over 100 billion. The reason for this decrease in numbers is that as we get older our brain ages and the number of neurons begins to decrease.

However, this does not mean that our neurons can only die. In our daily lives, not only do neurons degenerate, but they also regenerate.

It is currently believed that our brain is in constant neuronal regeneration . Thanks to the process known as neurogenesis, new neurons and new neuronal connections are created. Furthermore, some studies assure that, especially during childhood, we can promote this birth of new neurons through a series of exercises and activities that exercise our brain.

Main parts of the neuron

As mentioned above, the neuron constitutes the functional and structural unit not only of our brain, but of the entire nervous system. These are made up of different parts, each with specific characteristics and functions .

These parts are known as soma or cell body, dendrites and axon.

1. Soma or cell body

The first part we’ll talk about is the soma or cell body. As its name suggests, the soma is the centre of the neuron, and is where the metabolic activity of the neuron takes place .

New molecules are generated in the soma and all sorts of essential functions are carried out that make it possible to maintain the vitality of the cell and its functions,

In order to carry out these functions and achieve the transmission of information between neurons, each of them must produce huge amounts of proteins , without which this transmission would not be possible.

In addition, within the cell body we can find some organelles also present in other types of cells such as lysosomes and mitochondria, the Golgi apparatus or the very chromosomes that define our genetics. All this is located in the cytoplasm, which constitutes the soma of the neuron.

Finally, within the neuronal cytoplasm also are the fibrillar proteins, which form the cytoskeleton . This cytoskeleton is the one that shapes the neuron and provides a mechanism for the transport of the molecules.

2. Dendrites

Another part of the neurons are dendrites. This name refers to the numerous extensions in the form of small branches that are born from the neuronal body and whose main functions are to receive the stimuli and provide food to the cell.

These extensions function as neural terminals, which receive the action potentials of other nearby neurons and redirect them to the cell body or soma. In addition, due to their branched shape, along these we find the dendritic spines, small spines in which synapses are formed which make the transmission of bioelectric impulses possible .

3. Axon

Finally, the axon is the main (and largest) extension of the neuron. It is in charge of transporting the action potential from the cell body to another neuron .

This very long extension is born from the cell body or, sometimes, from a dendrite. Inside it we can find the axoplasm, a characteristically viscous substance in which the different organisms of the neurons are found.

One of the main characteristics of these axons is that they can be covered by a layer known as myelin sheath , which can enhance or facilitate the speed with which action potentials or electrical stimuli are transmitted.

In addition, neurons can be classified into different types according to axon length: Golgi neurons type I and type II, or according to their shape: pyramidal cells of the cerebral cortex and Purkinje cells.

4. Other neural elements

In addition to the main parts of the neuron described above, there are other particles or sections of great importance for the proper functioning of these. Some of these parts are:

Schwann cells

Also known as neurolemocytes, these cells line the axons of peripheral nervous system neurons and form myelin sheaths.

Myelin sheaths

As mentioned above, some axons have a myelin layer that facilitates the transmission of electrical stimuli over long distances .

Ranvier’s Nodules

This concept refers to the tiny spaces found in the myelin sheath and its main purpose is to enhance the speed with which electrical impulses are transmitted.