Seeing, hearing, tasting pleasant food, inhaling smells is a great gift man received from nature. All the diversity of the world around us is perceived indirectly: through various senses called the tentacles of the brain. During the evolutionary process, the organs of vision, hearing, smell, and touch adapted to the perception and analysis of a certain range of stimuli coming from both the internal environment of the body and the external environment. The problem arose before science: to explain the mechanisms of human perception of the surrounding world. For this, the concept of an analyzer was introduced into physiology.
This was done in 1908 by the brilliant Russian scientist I.P. Pavlov. How the doctrine of the methods of receiving, transcoding and analyzing the signals entering our body has evolved - these questions will be studied in this article.
What the analyzer consists of
IP Pavlov proposed the following anatomical diagram of the structure of a structure capable of receiving stimuli from the external and internal environment. It contains three parts: peripheral (receptor), conduction, and central (cortical). The physiologist identified five main - the leading complexes of the reception and transformation of information in the human body. These are visual, auditory, olfactory, gustatory and tactile, or tactile analyzers. Sensory systems are another term used in physiology to refer to a group of organs capable of receiving, transmitting and analyzing the flow of signals from surrounding reality. What properties do they have?
Adaptation is the main characteristic of the sensor system
The adaptation of nerve endings, pathways - nerves and a certain area of the brain - to various stimuli coming from internal organs and tissues, as well as from the outside, helps maintain the level of homeostasis of the human body. Correction of the perception of signals received at the receptors leads to the fact that with a high intensity, frequency and strength of the stimulus, the sensitivity of the peripheral part of the sensory system decreases, and with a low one it increases. The physiology of the analyzers has established their common property - quick adaptation to the degree of action of an external or internal signal. For example, the sensation of appetite and the sensitivity of the taste buds of the tongue decrease as the hunger is satisfied, since inhibition of the digestive nerve centers occurs. In addition to the five basic stimuli, our body is also able to feel temperature, pain, hunger, thirst. The concept of the analyzer was introduced into physiology after a thorough anatomical study of the structure of all the human senses in which the receptor fields of the corresponding sensory systems are located.
The principle of operation of the analyzer
All sensor systems function the same. For example, rods and cones of the retina change the quanta of light energy in the process of excitation. It is transmitted through the optic nerves to the subcortical centers and the visual zone of the cerebral cortex, located in the occipital part. In it, nerve impulses are analyzed and transcoded into visual images. On their basis, an adequate behavioral reaction of the body is formed. The very concept of the analyzer was introduced into physiology to explain the occurrence of a subjective reaction to stimuli, sensations and impressions, which are the basis of consciousness.
Modern ideas about the activity of sensory systems
The more alternative ways of implementing the process of perceiving the surrounding reality, the higher the level of human adaptive capabilities. That is why nerve impulses from the peripheral part of the analyzer can go to the central section along several reflex paths. For example, the physiology of sensory systems as a science has determined that visual sensations arise differently. For example, pulses from the retina receptors go through the optic nerves to the diencephalon (into the thalamus), then to the visual zone of the cerebral cortex. Or, visual images arise as follows: from the retina, the excitation enters the quadruple of the midbrain and from it into the central section. Each of the described reflex arcs carries out the process of perception of visual images, based on specific conditions and types of visual images.
The role of physiology of sensory systems in the development of science and technology
Sectors of human knowledge, such as robotics, neuro-linguistic programming, bionics and biophysics, introduce the main principles of the work of analyzers into their research - input, transcoding and output of information. The creation of sentient robots with artificial intelligence and the psyche became possible thanks to the discovery of principles such as multi-channel and multi-storey. That is why, at first, the concept of an analyzer was introduced into physiology, which, in connection with the complex mechanisms of its work, was then expanded by the introduction of a term such as a sensory system. This concept becomes leading in the study of the activity of the human nervous system.