The first thing we are going to do is know the etymological origin of the term neuron that concerns us now. In this case, it must be emphasized that it comes from Greek, exactly from the word “neuron”, which can be translated as “nerve”.
Likewise, we have to point out that this word is a neologism that was coined by the analyst and pathologist of German origin Heinrich Wilhelm Gottfried Waldeyer-Hartz (1836 – 1921). Specifically, it is considered that he gave shape to that term in his work titled “The Theory of the Neuron” (1891).
A neuron is a nerve cell that, through electrical and chemical signals, receives, processes and sends information . Neurons capture stimuli and conduct the nervous impulse through connections called synapses .
The body of the neuron can have various shapes. In it it is possible to detect different extensions, the most extensive being the axon . Precisely the axon, also known as the neurite , is responsible for the transmission of nerve impulses to other nerve cells, muscle or other types.
Thanks to synapses , neurons allow the interconnection of the various components of the nervous system . Thus, when a sensory area of the body registers a stimulus, the information in question is carried by neurons to the component in charge of offering a response. This new signal, in turn, is also transferred by neurons to execute some action (a secretion of a gland, a contraction of a muscle, a movement, etc.).
The neurons that convert external stimuli into internal ones are called sensory neurons or sensory neurons . Its activation occurs when hearing, touch or another sense captures the stimulus. The information is then sent by these neurons to the spinal cord or brain .
Efferent neurons or effector neurons , meanwhile, are dedicated to transporting nervous impulses out of the central nervous system, taking them to the glands or muscles .
If we take into account its function and its shape we can establish that reference is also made to the existence of other types of neurons:
-Interneurons, which are those neurons that directly connect with others. What this gives rise to is the creation of a broad neurological network, which in turn shapes really important processes such as, for example, thinking.
-Unipolar neurons, which have a single extension and are found, fundamentally, in invertebrates.
-Bipolar neurons, which have two opposing axons.
-Multipolar neurons, which are very abundant and can be of two classes or groups: the Golgi I, in which the pyramidal and Purkinje neurons are found, and the Golgi II.
-Pseudounipolar neurons, which are related to pain and touch. Of these, it should be noted that they seem to have a single axon, although they have two ends.
It is estimated that the adult human being has an average of 86,000 million neurons . These cells are organized into neuronal networks and also create neuronal circuits from their synaptic connections.