Afferent neurons carry nerve impulses from the receiving organs to the central nervous system.
The afferent adjective has its etymological origin in the Latin word affĕrens . In the broadest sense, this adjective applies to that which moves or carries something .
The notion is usually used in the field of biology and anatomy . An afferent is a formation whose function is to transmit substances or energy from one sector of the body to another more relevant in this context. By extension, the substances or stimuli that are transmitted in this way are called afferents.
afferent neurons
Afferent neurons , in this framework, are responsible for transporting nerve impulses from the receiving organs to the central nervous system ( CNS ); The reverse process is carried out by efferent neurons , which carry nerve impulses out of the CNS . These neurons have a single, long dendrite and a short axon; Its body has a rounded appearance and a smooth texture.
An afferent neuron, therefore, transfers the impulse to the CNS from the sectors that are located around it. A distinction can be made between visceral afferent neurons (which are responsible for stimuli coming from the viscera) and somatic afferent neurons (related to pain , temperature, etc.).
The sensory system is also known as the afferent system.
The perception of reality
In this context, we can say that human beings perceive the world around us through the physiological mechanisms that take place when we process afferent information; Some of the key points are the conversion into coded nervous activity from the energy coming from the stimulus, thanks to which we access data such as the location, intensity, duration and quality of the stimulus in question.
The encoding of action potentials gives rise to various temporal patterns, through various nerve fibers. This code is the representation of data that comes from the outside world and, as often happens when interpreting a symbol, it can differ considerably from the elements it represents.
Sometimes it happens that the encoded afferent information is incorporated into conscious knowledge of the material environment, that is, it has a conscious correlate. This type of information is known as sensory , while the experience of events and objects in the world around us that occurs consciously and enters through nervous processing is called perception .
The body of the afferent neuron is found in small ganglia that are located on both sides of the spinal column . It is divided into two portions: the peripheral fiber, which extends to a sensory ending and is the largest; that which penetrates the spinal cord through the dorsal root.
In the nervous system there are three phenomena that relate to each other in a kind of circle: sensation, decision and reaction . It is a process that takes place through the action of afferent neurons, efferent neurons and interneurons. A very common example can be contact with the flame of a candle, which is followed by a sensation of pain, after the information has been carried to the brain through afferent neurons, a reaction to the pain and a decision with regarding the way we will relate to fire in the future.
The afferent system and a type of arterioles
The afferent system , also known as the sensory system , is dedicated to the processing of sensory data. The five senses are part of the afferent system, which allows the stimulus to be received and then transmitted and enable the necessary response in each case, according to the characteristics of the stimulus in question.
Finally, the blood vessels that supply the nephrons (the most important functional units of the kidneys) are known as afferent arterioles . These vessels help regulate blood pressure .