Afferent Pathway And Efferent Pathway: The Types Of Nerve Fibers
It is natural to associate the concepts “neuron” and “brain.” After all, Neurons are the type of cell to which we normally attribute the possibility of thinking, reasoning and, in general, perform tasks related to intellect.
However, neurons are also an essential part of the nerves that run throughout our body (along with glial cells). It is not strange, if we take into account the function of these nerve fibers: make certain types of information travel through our organs and cellular tissues Now, although all these data transmission routes do basically the same thing, there are certain nuances and differences between them that make it possible for us to classify them according to their function. That is why we talk about the difference between afferent pathway and the efferent pathway.
Aference and efference: one letter changes everything
To understand the concepts of the afferent and the efferent, it is very useful to imagine the functioning of the nervous system as cognitive psychologists do, who They use the metaphor of the computer as a descriptive model of neural networks According to this metaphor, both the brain and the entire nervous system work in a similar way to how a computer does; It has a part of its structure dedicated to being in contact with the environment that surrounds it and another that is dedicated to working with data that it has stored and processed to obtain new information.
Thus, the neurons of the brain and spinal cord would be this “internal” part of the computer, while the nerves that sprout from the spinal column and reach the most remote corners of the body are the part in contact with the outside.
This last part of the nervous system, called peripheral nervous systemis where the afferent and efferent pathways meet, which They are the input and output channels of the central nervous system, respectively
The pathways through which sensory information travels
Thus, all the information that enters through the sensory neurons travels through the afferent pathways, that is, those that transform the information collected by the senses and transform them into nervous impulses On the other hand, the efferent pathways are responsible for propagating electrical impulses that are intended to activate (or deactivate) certain glands and muscle groups.
In this way, if we wanted to stick to a simple explanatory scheme about what an aference and an efference are, we would say that the first informs the central nervous system about what is happening in the rest of the body and the data about the environment that it is in. receives, while the efferent neurons are responsible for “transmitting the orders” and initiating the action.
Similarly, the word afferent serves to designate the information that travels through these pathways of the peripheral nervous system, while the term efference is used to refer to the output (or output) of data that goes from the central nervous system to muscle fibers and glands responsible for releasing all types of substances and hormones.
The distinction between the afferent and the efferent is very useful to understand how we perceive and act on the environment, but It can also be quite problematic because it is easy to confuse both terms and use them to designate the opposite of what is meant.
Fortunately, using simple mnemonic tricks it is very easy to remember what each thing is, and the fact that these words are only differentiated by one letter means that remembering one also means remembering the other. For example, the “a” of “afferent” can be related to the a of arrival (“arrival” and English), and the “e” of “efferent” with the first letter of “shipping.”
Pawn neurons?
The afferent and efferent pathways suggest a hierarchical functioning of the nervous system: while some neuronal groups inform about what is happening in the rest of the body and transmit orders to implement plans, strategies and action protocols, others make decisions and give orders that others will follow. However, the functioning of our nervous system is not as simple as can be intuited in this very schematic vision of the trips that nervous information makes throughout our body, for two basic reasons.
The first is that afferent and efferent neurons do not limit themselves to transmitting information passively: they also cause it to be transformed. What reaches the spinal cord and the glands and muscles is a burst of data whose shape depends largely on how it has found each and every one of the neurons through which it has traveled.
The second reason is that, although it is true that decision making depends more on the brain than on the neural networks of the peripheral nervous system, It is not clear who rules over whom, because they all occupy a place in a data cycle
Ultimately, the afferent neurons send information to the brain without which action plans cannot be initiated, and the way in which the efferent pathways transmit the information will have an impact on the body and the environment that will then affect the afferent neurons and, therefore, to the brain. Let’s think, for example, about keeping a box of cookies so as not to fall into the temptation of snacking between meals: a change in the environment causes us to think and feel differently than we would with the box of cookies in sight. .
In short, afferent and efferent neurons may have a simpler and easier task to study than the nerve cells of the brain, but they still play a vital role in our daily lives.
