С помощью анализаторов различных видов человек oriented in the outside world. It is through sight, hearing, smell, and other senses that we sense the external environment, we recognize hazards. Each person has different analyzers may not be developed equally. We will try to find out in the article what the olfactory analyzer is. The structure and function, the importance for the health of one of the senses are discussed in this article.
A person perceives most of the information about the world through the organ of vision, but without the smell, the picture would not be so bright and clear.
The olfactory system is designed torecognition of substances that are able to dissolve and have volatility. This system creates subjective images in the form of certain smells. The value of the olfactory analyzer is also in the fact that it is able to provide an objective assessment of the quality of air, food and the environment in general.
Если сравнивать орган обоняния у человека и animals, it can be said that for animals this organ has a special meaning. But it may not be developed equally for everyone. For example, there are life forms in which the olfactory analyzer is developed quite well. Thus, some species of butterflies can find their partner in smell at a distance of up to 8 kilometers. Everyone knows the dogs that can follow the trail of a person, guided by the smell of his things.
If we consider the functions of the olfactory analyzer, we can note the most important and significant ones:
It can be noted that in people who are blind, the sense of smell can be exacerbated, and they sense smells much better that help them navigate in this world.
If we consider the structure of this sense organ, then we can note the following sections:
We will get acquainted with the structure and functioning of these departments in more detail.
Considering the structure of the olfactory analyzer,must start with the initial department. It is located in the nasal cavity. In these places, the mucous membrane is slightly thickened, covered with mucous secretions from above, which play a protective role, protect against drying out, and also participate in removing the remaining stimuli after their exposure.
It is here that the contact between odorous substances and receptor cells. In the epithelium there are two types of cells:
Olfactory cells have two appendages, one of which passes to the olfactory bulbs, and the second has the shape of a stick and ends with a bubble with cilia.
This section is intended for carrying information, therefore it is represented by nerve paths that form the olfactory nerve. It consists of separate beams that go to the visual bump.
A connection with the limbic system, which explains the presence of emotions in the process of perceiving odors, has been observed. For example, some smells can cause pleasure, others - disgust, and so on.
This section includes the olfactory bulb. This includes the department in the temporal lobes of the brain.
All this is located in the anterior part of the pear-shaped lobe of the cortex in the hippocampus region.
For effective perception of irritating substancestheir molecules must first be dissolved in the mucus that surrounds the receptor cells. Then there is an interaction with special proteins embedded in the cell membrane.
Such contact is possible if the shape of the stimulus molecule corresponds to the shape of the protein. The mucous substance controls the accessibility of the surface of the receptor for odorous molecules.
After the stimulus molecule has enteredcontact with the receptor protein, a change in the structure of the latter occurs, as a result of which sodium ion channels in the membrane open. Sodium ions penetrate inside and create positive charges, which lead to membrane depolarization.
A mediator is released from the receptor cell, whichleads to the appearance of nerve impulses in the nerve fiber sections. Thus, in the form of nerve impulses, olfactory stimulation begins to be transmitted to other parts of the analyzer.
If we imagine how the olfactory analyzer of a person works, then all the work can be divided into several stages:
All these stages follow each other in succession. If there are problems or disturbances in one of them, we can say that the perception of odors is disturbed.
We dismantled the features of the olfactory analyzer of a person, but it is also worth noting that this sensory system is able to adapt. This happens with prolonged exposure to the stimulus.
Analyzer adaptation can occur within a few seconds, and sometimes it takes up to five minutes. It all depends on a number of factors:
Имеется достаточно обширная группа пахучих substances to which the olfactory analyzer adapts quickly. Very little time passes and the smell ceases to be felt. A striking example is the complete adaptation to the smell of your body, room, things.
To some irritants addictive formsslowly or only partially. When exposed to a weak olfactory irritant for a short time, habituation may manifest itself in the form of an increase in the sensitivity of this analyzer.
It has already been established that the development of adaptationdoes not occur in the first section of the analyzer, but in the last, that is, cortical. Often, when the same odorous substance acts for a long time, a stable focus of excitation is formed in the cortex of the big hemispheres. In these situations, the smell can also occur when exposed to other stimuli. Sometimes this feeling can become annoying and appears even in the absence of stimuli. In this case, we can talk about hallucinations, or illusions.
We can only say with certainty that ifadaptation to one particular smell is observed, this will not affect the perception of other stimuli, since all the stimuli affect different receptors.
Currently, more than 10 thousand odorous substances are known. All of them can be grouped into seven classes of primary odors:
If there is a mixture of several smells, thenolfactory analyzer can be perceived as a completely new flavor. Molecules of different substances differ in different forms, for example, camphor odor has round molecules, and musky - in the form of a disk. In addition, they also differ in electric charge: some may have a positive and others negative.
There are many theories that tryexplain the mechanism of perception of odors. Currently, the most common is stereochemical, which states that there are several types of sites on the membrane of receptor cells. They are distinguished by their structure and electrophilicity. They are able to recognize odorous molecules of a certain shape and size.
In addition, the olfactory analyzer is not equally developed at all, moreover, some violations and deviations in its work can be observed:
It should be noted that with age occursgradual decrease in olfactory sensitivity. The olfactory analyzer is no longer capable of so clearly and quickly recognizing odors. Scientists estimate that by age 50, the average person’s sense of smell is reduced by half compared to youth.
The very first during fetal developmentolfactory analyzer begins to form a peripheral section. This happens already at the 8th week of development. By the end of pregnancy, or rather, by the end of 8 months, this analyzer is already fully formed.
Immediately after birth, you can observe the reaction of the newborn to smells. This is manifested in the form of mimic movements, changes in the work of the heart muscle, respiratory rate, body position.
With the help of smell, the baby recognizes the smellmy mother. This sense organ is an important component of the formation of food reflexes. Gradually, when the child grows up, there is an increase in the ability of the analyzer to differentiate odors. The subtlety and strength of this process increases by 4 months.
If we compare the ability to perceive and differentiate odors in children 5-6 years old and in adults, then we can say that in the latter it is much higher.
These are the age features of the olfactoryanalyzer. You can also say that as a result of systematic workouts, you can significantly improve your sense of smell, but heavy smokers run the risk of losing their sharpness of perception, since the constituent components of tobacco smoke negatively affect the receptors. Also, frequent inflammatory diseases of the nasal cavity contribute to the reduction of smell.
Вот мы и рассмотрели обонятельный анализатор.The structure and its functions are described with all possible accessibility. It is safe to say that all the senses are important for a person. If there are problems in the work of at least one analyzer, then we can already say that the adequacy of perception of the surrounding world decreases, the fullness of sensations from life disappears. Take care of yourself and your senses.
