Conclusion about the importance of reflexes in human life. Conditioned reflexes and their meaning. When conditioned reflexes fade

I. P. Pavlov divided all reflex reactions of the body to various stimuli into two groups: unconditioned and conditional.
Unconditioned reflexes are innate reflexes inherited from parents. They are specific, relatively permanent and are carried out by the lower parts of the central nervous system - the spinal cord, brain stem and subcortical nuclei of the brain.

Unconditioned reflexes (for example, sucking, swallowing, pupillary reflexes, coughing, sneezing, etc.) are preserved in animals lacking large hemispheres. They are formed in response to the action of certain stimuli. So, the salivation reflex occurs when food stimulates the taste buds of the tongue. The resulting excitation in the form of a nerve impulse is carried along the sensory nerves to the medulla oblongata, where the center of salivation is located, from where it is transmitted along the motor nerves to the salivary glands, causing salivation. Based unconditioned reflexes regulation and coordinated activity of various organs and their systems are carried out, the very existence of the organism is supported.

In changing environmental conditions, the preservation of the vital activity of the organism and adaptive behavior is carried out due to the formation of conditioned reflexes with the obligatory participation of the cortex. hemispheres brain. They are not congenital, but are formed during life on the basis of unconditioned reflexes under the influence of certain environmental factors. Conditioned reflexes are strictly individual, i.e., in some individuals of a species, this or that reflex may be present, while in others it may be absent.

unconditioned reflexes. The value of unconditioned reflexes

Maintaining the constancy of the internal environment (homeostasis);
- preservation of the integrity of the body (protection from damaging environmental factors);
- reproduction and conservation of the species as a whole.

Unconditioned reflexes and their significance for the development of the child

Birth is a big shock for the child's body. From a vegetative, vegetative existence in a relatively constant environment (the mother's organism), he suddenly passes into completely new conditions of the air environment with an infinite number of frequently changing stimuli, into the world where he has to become a rational person.

The life of a child in new conditions is provided by innate mechanisms. It is born with a certain willingness of the nervous system to adapt the body to external conditions. So, immediately after birth, reflexes are activated that ensure the work of the main body systems (respiration, blood circulation - approx. site). In the early days, you can also note the following. Strong skin irritation (an injection, for example) causes a protective withdrawal, the flashing of an object in front of the face causes squinting, and a sharp increase in the brightness of light causes pupil constriction, etc. These reactions are protective reflexes.

In addition to protective ones, reactions aimed at contact with an irritant can be detected in newborns. These are orienting reflexes. Observations have established that already in the period from the first to the third day, a strong light source causes the head to turn: in the children's room of the maternity hospital on a sunny day, the heads of most newborns, like sunflowers, are turned towards the light. It has also been proven that already in the first days of the newborn it is common to follow a slowly moving light source. Orientation-food reflexes are also easily evoked. Touching the corners of the lips, cheeks causes a search reaction in a hungry child: he turns his head towards the stimulus, opens his mouth.
In addition to those listed, the child has several more innate reactions: a sucking reflex - the child immediately begins to suck the object put into his mouth; grasping reflex - touching the palm causes a grasping reaction; repulsion (crawling) reflex - when touching the soles of the feet and some other reflexes.

Thus, the child is armed with a certain number of unconditioned reflexes that appear in the very first days after birth. In recent years, scientists have proven that some reflex reactions appear even before birth. So, after eighteen weeks, the fetus develops a sucking reflex.

Most inborn reactions are necessary for a child to live. They help him to adapt to the new conditions of existence. Thanks to these reflexes, a new type of breathing and nutrition becomes possible for the newborn. If before birth the fetus develops at the expense of the mother's body (through the walls of the vessels of the placenta - the child's place - nutrients and oxygen enter the blood of the fetus from the mother's blood), then after birth the child's body switches to pulmonary breathing and the so-called oral nutrition (through the mouth and stomach). -intestinal tract). This adaptation occurs reflexively. After the lungs are filled with air, the whole system of muscles is included in the rhythmic respiratory movements. Breathing is easy and free. Feeding occurs through the sucking reflex. The innate actions included in the sucking reflex are at first poorly coordinated with each other: when sucking, the child chokes, suffocates, his strength quickly runs out. All his activity is directed to sucking for the sake of saturation. The establishment of reflex automatism of thermoregulation is also very important: the child's body is getting better and better adapted to temperature changes.

Education and biological significance conditioned reflexes

Conditioned reflexes are formed as a result of a combination of an unconditioned reflex with the action of a conditioned stimulus. For this, two conditions must be met:

1) the action of the conditioned stimulus must necessarily somewhat precede the action of the unconditioned stimulus;

2) the conditioned stimulus must be repeatedly reinforced by the action of the unconditioned stimulus.

The mechanism for the formation of a conditioned reflex consists in establishing a temporary connection (short circuit) between two foci of excitation in the mayor of the brain. For the considered example, such foci are the centers of salivation and hearing.
The arc of the conditioned reflex, in contrast to that of the unconditioned reflex, is much more complicated and includes receptors that perceive conditioned irritation, a sensory nerve that conducts excitation to the brain, a section of the cortex associated with the center of the unconditioned reflex, a motor nerve and a working organ.

Conditioned reflexes in higher animals, and especially in humans, are developed constantly. This phenomenon is explained by the dynamism of the external environment, to the constantly changing conditions of which the nervous system must quickly adapt.
Thus, if unconditioned reflexes give only a strictly limited orientation in the environment, then conditioned reflexes provide a universal orientation.

The biological significance of conditioned reflexes in the life of humans and animals is enormous, since they provide their adaptive behavior - they allow you to accurately navigate in space and time, find food (by sight, smell), avoid danger, eliminate harmful effects for the body. With age, the number of conditioned reflexes increases, the experience of behavior is acquired, thanks to which the adult organism is better adapted to the environment than the child's.



I. P. Pavlov divided all reflex reactions of the body to various stimuli into two groups: unconditioned and conditional.
Unconditioned reflexes are innate reflexes inherited from parents. They are specific, relatively permanent and are carried out by the lower parts of the central nervous system - the spinal cord, brain stem and subcortical nuclei of the brain.

Unconditioned reflexes (for example, sucking, swallowing, pupillary reflexes, coughing, sneezing, etc.) are preserved in animals lacking large hemispheres. They are formed in response to the action of certain stimuli. So, the salivation reflex occurs when food stimulates the taste buds of the tongue. The resulting excitation in the form of a nerve impulse is carried along the sensory nerves to the medulla oblongata, where the center of salivation is located, from where it is transmitted along the motor nerves to the salivary glands, causing salivation. On the basis of unconditioned reflexes, the regulation and coordinated activity of various organs and their systems are carried out, the very existence of the organism is supported.

In changing environmental conditions, the preservation of the vital activity of the organism and adaptive behavior is carried out due to the formation of conditioned reflexes with the obligatory participation of the cerebral cortex. They are not congenital, but are formed during life on the basis of unconditioned reflexes under the influence of certain environmental factors. Conditioned reflexes are strictly individual, i.e., in some individuals of a species, this or that reflex may be present, while in others it may be absent.

unconditioned reflexes. The value of unconditioned reflexes

Maintaining the constancy of the internal environment (homeostasis);
- preservation of the integrity of the body (protection from damaging environmental factors);
- reproduction and conservation of the species as a whole.

Unconditioned reflexes and their significance for the development of the child

Birth is a big shock for the child's body. From a vegetative, vegetative existence in a relatively constant environment (the mother's organism), he suddenly passes into completely new conditions of the air environment with an infinite number of frequently changing stimuli, into the world where he has to become a rational person.

The life of a child in new conditions is provided by innate mechanisms. It is born with a certain willingness of the nervous system to adapt the body to external conditions. So, immediately after birth, reflexes are activated that ensure the operation of the main body systems (respiration, blood circulation - approx. biofile.ru). In the early days, you can also note the following. Strong skin irritation (an injection, for example) causes a protective withdrawal, the flashing of an object in front of the face causes squinting, and a sharp increase in the brightness of light causes pupil constriction, etc. These reactions are protective reflexes.

In addition to protective ones, reactions aimed at contact with an irritant can be detected in newborns. These are orienting reflexes. Observations have established that already in the period from the first to the third day, a strong light source causes the head to turn: in the children's room of the maternity hospital on a sunny day, the heads of most newborns, like sunflowers, are turned towards the light. It has also been proven that already in the first days of the newborn it is common to follow a slowly moving light source. Orientation-food reflexes are also easily evoked. Touching the corners of the lips, cheeks causes a search reaction in a hungry child: he turns his head towards the stimulus, opens his mouth.
In addition to those listed, the child has several more innate reactions: a sucking reflex - the child immediately begins to suck the object put into his mouth; grasping reflex - touching the palm causes a grasping reaction; repulsion (crawling) reflex - when touching the soles of the feet and some other reflexes.

Thus, the child is armed with a certain number of unconditioned reflexes that appear in the very first days after birth. Behind last years scientists have proven that some reflex reactions appear even before birth. So, after eighteen weeks, the fetus develops a sucking reflex.

Most inborn reactions are necessary for a child to live. They help him to adapt to the new conditions of existence. Thanks to these reflexes, a new type of breathing and nutrition becomes possible for the newborn. If before birth the fetus develops at the expense of the mother's body (through the walls of the vessels of the placenta - the child's place - nutrients and oxygen enter the blood of the fetus from the mother's blood), then after birth the child's body switches to pulmonary breathing and the so-called oral nutrition (through the mouth and stomach). -intestinal tract). This adaptation occurs reflexively. After the lungs are filled with air, the whole system of muscles is included in the rhythmic respiratory movements. Breathing is easy and free. Feeding occurs through the sucking reflex. The innate actions included in the sucking reflex are at first poorly coordinated with each other: when sucking, the child chokes, suffocates, his strength quickly runs out. All his activity is directed to sucking for the sake of saturation. Highly great importance It also has the establishment of reflex automatism of thermoregulation: the child's body is getting better and better adapted to temperature changes.

Formation and biological significance of conditioned reflexes

Conditioned reflexes are formed as a result of a combination of an unconditioned reflex with the action of a conditioned stimulus. For this, two conditions must be met:

1) the action of the conditioned stimulus must necessarily somewhat precede the action of the unconditioned stimulus;

2) the conditioned stimulus must be repeatedly reinforced by the action of the unconditioned stimulus.

The mechanism for the formation of a conditioned reflex consists in establishing a temporary connection (short circuit) between two foci of excitation in the mayor of the brain. For the considered example, such foci are the centers of salivation and hearing.
The arc of the conditioned reflex, in contrast to that of the unconditioned reflex, is much more complicated and includes receptors that perceive conditioned irritation, a sensory nerve that conducts excitation to the brain, a section of the cortex associated with the center of the unconditioned reflex, a motor nerve and a working organ.

Conditioned reflexes in higher animals, and especially in humans, are developed constantly. This phenomenon is explained by the dynamism of the external environment, to the constantly changing conditions of which the nervous system must quickly adapt.
Thus, if unconditioned reflexes give only a strictly limited orientation in the environment, then conditioned reflexes provide a universal orientation.

The biological significance of conditioned reflexes in the life of humans and animals is enormous, since they provide their adaptive behavior - they allow you to accurately navigate in space and time, find food (by sight, smell), avoid danger, eliminate harmful effects for the body. With age, the number of conditioned reflexes increases, the experience of behavior is acquired, thanks to which the adult organism is better adapted to the environment than the child's.

The biological significance of conditioned reflexes lies in the fact that they make it possible to adapt much better and more accurately to the conditions of existence and survive in these conditions.

As a result of the formation of conditioned reflexes, the body reacts not only directly to unconditioned stimuli, but also to the possibility of their action on it; reactions appear some time before unconditional irritation. This very organism turns out to be prepared in advance for the actions that it has to carry out in a given situation. Conditioned reflexes help to find food, avoid danger in advance, eliminate harmful influences, etc.

The adaptive significance of conditioned reflexes is also manifested in the fact that the precedence of a conditioned stimulus to an unconditioned one strengthens the unconditioned reflex and accelerates its development.

The student learns about conditioned and unconditioned reflexes even at the first lessons of zoology, when a vivid example of the “Pavlov’s dog” is given, which begins to salivate after a certain signal is given. Then the student gets the first idea about the role of reflexes in human life and about the existence of the so-called "first signal system". However, beyond school curriculum there remains such a thing as a “second signaling system”, which is no less important.

The role of the system of conditioned and unconditioned reflexes in human life

What are the types of reflexes, what is the difference between conditioned reflexes and unconditioned ones, and what is their significance?

For example, you burned your finger with a match and pull your hand away, and immediately, without hesitation. Painful irritation of the skin was transmitted by nerve fibers to a group of cells in the central nervous system that are in charge of the motor functions of the muscles of the hands. The excitement that arose in them was immediately transmitted along other nerve fibers to the muscles. They contracted sharply - the hand twitched, the fire no longer burns the finger. This type of human reflex is called unconditioned, there are many such reflexes and they are all congenital.

And conditional reflexes need to be created, worked out. Research in this area is associated with the name of our famous physiologist IP Pavlov. It was this scientist who substantiated the importance of reflexes in human life and proved that if the system of unconditioned reflexes is repeatedly accompanied by a certain stimulus, then after a while the stimulus will begin to cause this reflex.

Here is an example. You are pricked with a needle and at the same time the bell is rung. After a certain number of repetitions, the sound of the bell becomes a signal to withdraw the hand. The needle did not prick, and the hand twitched involuntarily. The conditioned reflex has been created.

Conditioned and unconditioned human reflexes play an important role in life. The child, having been burned by fire, further withdraws his hand before the fire again scorches his skin. A forest animal, having become intimately acquainted with some kind of danger, behaves more cautiously at another time. IP Pavlov called this perception of the surrounding reality by the human and animal brain the first signal system.

In addition, a person has a second signaling system. In this case, the conditioned stimulus is words-images and concepts. If, say, a person has experienced the strongest fright associated with a fire, then with him it is enough to shout “Fire!” To cause the same fright.

Both signal systems of conditioned reflexes in our body are closely interconnected. They represent the work of our central nervous system. And the latter regulates all the activities of the body. It is known that various emotional experiences (fear, grief, joy, etc.) can cause changes in the work of the heart (acceleration and slowing of the heartbeat, constriction or expansion of blood vessels, redness or blanching of the skin), can lead to gray hair and so on. This means that in one way or another we can influence the work of many internal organs, including the word. It can significantly affect the psyche, and therefore, the work of the whole organism.

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Conditioned and unconditioned reflexes are characteristic of the entire animal world.

In biology, they are considered as the result of a long evolutionary process and represent the response of the central nervous system to external environmental influences.

They provide a very fast response to a particular stimulus, which significantly saves the resources of the nervous system.

Classification of reflexes

AT modern science such reactions are described using several classifications that describe their features in different ways.

So, they are of the following types:

1. Conditional and unconditional - depending on how they are formed.
2. Exteroreceptive (from "extra" - external) - reactions of external receptors of the skin, hearing, smell and vision. Interoreceptive (from "intero" - inside) - reactions of internal organs and systems. Proprioceptive (from "proprio" - special) - reactions associated with the sensation of one's own body in space and formed by the interaction of muscles, tendons and joints. This is a classification by type of receptor.
3. According to the type of effectors (zones of a reflex response to information collected by receptors), there are: motor and vegetative.
4. Classification based on a certain biological role. Allocate species aimed at protection, nutrition, orientation in the environment and reproduction.
5. Monosynaptic and polysynaptic - depending on the complexity of the neural structure.
6. According to the type of influence, excitatory and inhibitory reflexes are distinguished.
7. And according to where the reflex arcs are located, they distinguish cerebral (various parts of the brain are included) and spinal (spinal cord neurons are included).

What is a conditioned reflex

This is a term denoting a reflex formed as a result of the fact that at the same time for a long time a stimulus that does not cause any reaction is presented with the stimulus that causes some specific unconditioned reflex. That is, the reflex response as a result extends to an initially indifferent stimulus.

Where are the centers of conditioned reflexes located?

Since this is a more complex product of the nervous system, the central part of the neural arc of conditioned reflexes is located in the brain, and specifically in the cerebral cortex.

Examples of conditioned reflexes

The most striking and classic example is Pavlov's dog. The dogs were presented with a piece of meat (this caused the secretion of gastric juice and salivation) along with the inclusion of a lamp. As a result, after a while, the process of activating digestion started when the lamp was turned on.

A familiar example from life is the feeling of cheerfulness from the smell of coffee. Caffeine does not yet directly affect the nervous system. He is outside the body - in a circle. But the feeling of cheerfulness is turned on only from the smell.

Many mechanical actions and habits are also examples. They rearranged the furniture in the room, and the hand reaches in the direction where the closet used to be. Or the cat that runs to the bowl when it hears the rustle of the food box.

The difference between unconditioned reflexes and conditioned

They differ in that the unconditional are innate. They are the same for all animals of one species or another, as they are inherited. They are quite invariable throughout the life of a person or animal. From birth and always occur in response to receptor irritation, and are not produced.

Conditionals are acquired during life, with experience in interaction with the environment. Therefore, they are quite individual - depending on the conditions under which it was formed. They are fickle throughout life and can die out if they are not reinforced.

Conditioned and unconditioned reflexes - comparative table

The difference between instincts and unconditioned reflexes

An instinct, like a reflex, is a biologically significant form of animal behavior. Only the second is a simple short response to a stimulus, and instinct is a more complex activity that has a specific biological purpose.

The unconditioned reflex is always triggered. But instinct is only in a state of biological readiness of the body and start this or that behavior. For example, mating behavior in birds only kicks in at certain times of the year, when chick survival can be at its maximum.

What is not characteristic of unconditioned reflexes

In short, they cannot change throughout life. Do not differ in different animals of the same species. They cannot disappear or stop appearing in response to a stimulus.

When conditioned reflexes fade

Extinction occurs as a result of the fact that the stimulus (stimulus) ceases to coincide in time of presentation with the stimulus that caused the reaction. They need reinforcements. Otherwise, without being reinforced, they lose their biological significance and fade away.

Unconditioned reflexes of the brain

These include the following types: blinking, swallowing, vomiting, indicative, balance maintenance associated with hunger and satiety, inhibition of movement in inertia (for example, with a push).

Violation or disappearance of any of these types of reflexes can be a signal of serious disorders in the brain.

Pulling your hand away from a hot object is an example of what kind of reflex

An example of a pain reaction is pulling your hand away from a hot kettle. It's an unconditional view, response of the body to the dangerous effects of the environment.

Blink reflex - conditioned or unconditioned

Blinking reaction is an unconditioned species. It occurs as a result of dryness of the eye and to protect against mechanical damage. All animals and humans have it.

Salivation in a person at the sight of a lemon - what a reflex

This is a conditional view. It is formed because the rich taste of lemon provokes salivation so often and strongly that as a result of simply looking at it (and even remembering it), a response is triggered.

How to develop a conditioned reflex in a person

In humans, unlike animals, a conditional view is developed faster. But for all the mechanism is the same - the joint presentation of incentives. One, causing an unconditioned reflex, and the other - indifferent.

For example, for a teenager who fell off a bicycle to some particular music, later unpleasant feelings arising to the same music may become the acquisition of a conditioned reflex.

What is the role of conditioned reflexes in the life of an animal

They enable an animal with rigid, unchanging unconditional reactions and instincts to adapt to conditions that are constantly changing.

At the level of the whole species, this is an opportunity to live in the largest possible areas with different weather conditions, with different levels of food supply. In general, they make it possible to react flexibly and adapt to the environment.

Conclusion

Unconditioned and conditioned responses are essential to the survival of the animal. But it is in interaction that they allow to adapt, multiply and grow the most healthy offspring.

A reflex is the body's response to an internal or external stimulus, carried out and controlled by the central nervous system. Our compatriots I.P. Pavlov and I.M. Sechenov.

What are unconditioned reflexes?

An unconditioned reflex is an innate stereotyped reaction of the body to the influence of the internal or environment, inherited from the offspring from the parents. It remains with a person throughout his life. Reflex arcs pass through the brain and the cerebral cortex does not take part in their formation. The significance of the unconditioned reflex is that it ensures the adaptation of the human body directly to those changes in the environment that often accompanied many generations of his ancestors.

What reflexes are unconditioned?

The unconditioned reflex is the main form of activity of the nervous system, an automatic response to a stimulus. And since various factors affect a person, then the reflexes are different: food, defensive, indicative, sexual ... Salivation, swallowing and sucking are food. Defensive are coughing, blinking, sneezing, withdrawal of limbs from hot objects. orienting reactions can be called turning the head, squinting the eyes. Sexual instincts include reproduction, as well as caring for offspring. The value of the unconditioned reflex lies in the fact that it ensures the preservation of the integrity of the body, maintains the constancy of the internal environment. Thanks to him, reproduction occurs. Even in newborns, an elementary unconditioned reflex can be observed - this is sucking. By the way, it is the most important. The irritant in this case is the touch to the lips of an object (nipples, mother's breasts, toys or fingers). Another important unconditioned reflex is blinking, which occurs when a foreign body approaches the eye or touches the cornea. This reaction refers to the protective or defensive group. It is also observed in children, for example, when exposed to strong light. However, the signs of unconditioned reflexes are most pronounced in various animals.

What are conditioned reflexes?

Reflexes acquired by the body during life are called conditioned reflexes. They are formed on the basis of inherited ones, subject to the influence of an external stimulus (time, knock, light, and so on). A vivid example is the experiments carried out on dogs by Academician I.P. Pavlov. He studied the formation of this type of reflexes in animals and was the developer of a unique technique for obtaining them. So, to develop such reactions, it is necessary to have a regular stimulus - a signal. It starts the mechanism, and repeated repetition of the stimulus effect allows you to develop. In this case, a so-called temporary connection arises between the arcs of the unconditioned reflex and the centers of the analyzers. Now the basic instinct is awakening under the action of fundamentally new signals of an external nature. These stimuli of the surrounding world, to which the body was previously indifferent, begin to acquire exceptional, vital importance. Each living being can develop many different conditioned reflexes during his life, which form the basis of his experience. However, this applies only to this particular individual, by inheritance this life experience will not be transmitted.

An independent category of conditioned reflexes

In an independent category, it is customary to single out conditioned reflexes of a motor nature developed during life, that is, skills or automated actions. Their meaning lies in the development of new skills, as well as the development of new motor forms. For example, over the entire period of his life, a person masters many special motor skills that are associated with his profession. They are the basis of our behavior. Thinking, attention, consciousness are freed when performing operations that have reached automatism and become a reality. Everyday life. The most successful way of mastering the skills is the systematic implementation of the exercise, the timely correction of the noticed mistakes, as well as the knowledge of the ultimate goal of any task. In the event that the conditioned stimulus is not reinforced for some time by the unconditioned stimulus, its inhibition occurs. However, it does not completely disappear. If, after some time, the action is repeated, the reflex will quickly recover. Inhibition can also occur under the condition of the appearance of an irritant of even greater force.

Compare unconditioned and conditioned reflexes

As mentioned above, these reactions differ in the nature of their occurrence and have a different formation mechanism. In order to understand what the difference is, just compare unconditioned and conditioned reflexes. So, the first are present in a living being from birth, during the whole life they do not change and do not disappear. In addition, unconditioned reflexes are the same in all organisms of a particular species. Their meaning is to prepare the living being for constant conditions. The reflex arc of such a reaction passes through the trunk of the brain or spinal cord. As an example, here are some (congenital): active salivation when a lemon enters the mouth; sucking movement of the newborn; coughing, sneezing, pulling hands away from a hot object. Now consider the characteristics of conditioned reactions. They are acquired throughout life, can change or disappear, and, no less important, they are individual (their own) for each organism. Their main function is the adaptation of a living being to changing conditions. Their temporary connection (centers of reflexes) is created in the cerebral cortex. An example of a conditioned reflex is the reaction of an animal to a nickname, or the reaction of a six-month-old child to a bottle of milk.

Scheme of the unconditioned reflex

According to the research of academician I.P. Pavlov, the general scheme of unconditioned reflexes is as follows. Some or other stimuli of the internal or external world of the organism act on certain receptor nervous devices. As a result, the resulting irritation transforms the entire process into the so-called phenomenon of nervous excitation. It is transmitted through nerve fibers (as through wires) to the central nervous system, and from there it goes to a specific working organ, already turning into a specific process at the cellular level of this part of the body. It turns out that these or those irritants are naturally connected with this or that activity in the same way as the cause with the effect.

Features of unconditioned reflexes

The characteristic of unconditioned reflexes presented below, as it were, systematizes the material presented above, it will help to finally understand the phenomenon we are considering. So, what are the features of inherited reactions?

Unconditional instinct and animal reflex

The exceptional constancy of the neural connection underlying unconditional instinct, due to the fact that all animals are born with a nervous system. She is already able to respond properly to specific environmental stimuli. For example, a creature might flinch at a harsh sound; he will secrete digestive juice and saliva when food enters the mouth or stomach; it will blink with visual stimulation, and so on. Innate in animals and humans are not only individual unconditioned reflexes, but also much more complex forms of reactions. They are called instincts.

The unconditioned reflex, in fact, is not a completely monotonous, stereotyped, transfer reaction of an animal to an external stimulus. It is characterized, though elementary, primitive, but still by variability, variability, depending on external conditions (strength, peculiarities of the situation, position of the stimulus). In addition, it is also influenced by the internal states of the animal (reduced or increased activity, posture, and others). So, even I.M. Sechenov, in his experiments with decapitated (spinal) frogs, showed that when the toes of the hind legs of this amphibian are acted upon, the opposite motor reaction occurs. From this we can conclude that the unconditioned reflex still has adaptive variability, but within insignificant limits. As a result, we find that the balancing of the organism and the external environment achieved with the help of these reactions can be relatively perfect only in relation to slightly changing factors of the surrounding world. The unconditioned reflex is not able to ensure the adaptation of the animal to new or dramatically changing conditions.

As for the instincts, sometimes they are expressed in the form of simple actions. For example, a rider, thanks to his sense of smell, looks for the larvae of another insect under the bark. He pierces the bark and lays his egg in the found victim. This is the end of all its action, which ensures the continuation of the genus. There are also complex unconditioned reflexes. Instincts of this kind consist of a chain of actions, the totality of which ensures the continuation of the species. Examples include birds, ants, bees and other animals.

Species specificity

Unconditioned reflexes (species) are present in both humans and animals. It should be understood that such reactions in all representatives of the same species will be the same. An example is a turtle. All species of these amphibians retract their heads and limbs into their shells when threatened. And all the hedgehogs jump up and make a hissing sound. In addition, you should be aware that not all unconditioned reflexes occur at the same time. These reactions change according to age and season. For example, the breeding season or the motor and sucking actions that appear in an 18-week-old fetus. Thus, unconditioned reactions are a kind of development for conditioned reflexes in humans and animals. For example, in young children, as they grow older, there is a transition to the category of synthetic complexes. They increase the adaptability of the body to external environmental conditions.

Unconditional braking

In the process of life, each organism is regularly exposed - both from the outside and from the inside - to various stimuli. Each of them is able to cause a corresponding reaction - a reflex. If all of them could be realized, then the vital activity of such an organism would become chaotic. However, this does not happen. On the contrary, reactionary activity is characterized by consistency and orderliness. This is explained by the fact that inhibition of unconditioned reflexes occurs in the body. This means that the most important reflex at a particular moment of time delays the secondary ones. Usually, external inhibition can occur at the time of the start of another activity. The new exciter, being stronger, leads to the attenuation of the old one. And as a result, the previous activity will automatically stop. For example, a dog is eating and at that moment the doorbell rings. The animal immediately stops eating and runs to meet the visitor. There is an abrupt change in activity, and the dog's salivation stops at that moment. Certain innate reactions are also referred to as unconditional inhibition of reflexes. In them, certain pathogens cause a complete cessation of some actions. For example, the anxious clucking of a chicken causes the chickens to freeze and cling to the ground, and the onset of darkness forces the kenar to stop singing.

In addition, there is also a protective id that arises as a response to a very strong stimulus that requires actions from the body that exceed its capabilities. The level of such exposure is determined by the frequency of impulses of the nervous system. The stronger the neuron is excited, the higher the frequency of the flow of nerve impulses that it generates will be. However, if this flow exceeds certain limits, then a process will occur that will begin to prevent the passage of excitation through the neural circuit. The flow of impulses along the reflex arc of the spinal cord and brain is interrupted, as a result, inhibition occurs, which preserves the executive organs from complete exhaustion. What follows from this? Thanks to the inhibition of unconditioned reflexes, the body secretes from all options the most adequate, capable of protecting against unbearable activities. This process also contributes to the manifestation of the so-called biological caution.