Sensitivity (we consider the concept within the framework of physiology) is one of the most important properties that both a person and any other living organism possess. Therefore, it requires detailed consideration. In the article we will present the types of sensitivity according to a number of classifications, as well as the types of its violations.

What is this?

All types of sensitivity in physiology are:

• Part of the reception perceived by the psyche. Reception - afferent impulsation entering the departments of the central nervous system.
• The ability of a living organism to perceive various stimuli that come from both its own organs and tissues, and from the environment.
• The ability of the organism, preceding a differentiated response to a stimulus - reactivity.

And now - the classification of types of sensitivity.

General sensitivity

Several groups stand out here at once - we will present their content separately.

The exteroceptive type (superficial sensitivity) within itself is divided into:

• tactile (rough);
• painful;
• temperature (cold and heat).

Proprioceptive type (deep sensitivity) - a sense of oneself in space, the position of one's body, limbs relative to each other. This view has the following categories:

• feeling of own body weight, pressure;
• vibration;
• sense of touch (tactile light);
• joint-muscular;
• kinesthesia (the so-called determination of the movement of skin folds).

Complex types of sensitivity:

• The feeling is two-dimensional and spatial - with its help we determine the place of touch to our body. It helps to find out what symbol, number or letter is "written" on the skin with the finger of another person.
• Interoceptive - this sensitivity causes irritation of internal organs.
• Discriminatory - helps to distinguish between touches, skin injections that are applied at a close distance to each other.
• Stereognosis - this type of sensitivity helps to recognize a particular object by touch.

As for the above examples, their identification will be possible only with further input and processing of the impulse from the primary cortical layer of the analyzer (it will be the central posterior gyrus) into associative or secondary cortical fields. The latter are predominantly located in the parieto-postcentral zones, in the lower and upper parietal lobes.

Let's move on to the next classification.

General and special sensitivity

The same concepts are used here, only for a slightly different classification.

General sensitivity is divided into simple and complex.

Special sensitivity is represented by the following categories:

• visual;
• taste;
• olfactory;
• auditory.

Complicated Sensitivity

In this classification, we will consider various types of sensitivity - characteristic not only for humans, but for all living beings in general.

It's the following:

• Vision is the body's perception of light.
• Echolocation, hearing - perception by living systems of sounds.
• Smell, taste, stereochemical sense (typical for insects and hammerhead sharks) - the chemical sensitivity of the body.
• Magnetoreception - the ability of a living being to feel the magnetic field, which allows you to navigate the terrain, determine the height, plan the movement of your own body. The type of sensitivity is characteristic of some sharks.
• Electroreception - the ability to sense the electrical signals of the surrounding world. Used to find prey, orientation, various forms biocommunications.

According to phylogenetic criteria of formation

The classification was proposed by the scientist G. Head. There are two kinds of sensitivity of a human being, a living being:

• Protopathic. A primitive form that has its center in the thalamus. Cannot give a precise definition of the localization of the source of irritation - neither external nor inside one's own body. It no longer reflects objective states, but subjective processes. Protopathic sensitivity ensures the perception of the strongest, coarsest forms of stimuli, pain and temperature, which are dangerous to the body.
• Epicritical. Has a cortical center, is more differentiated, objectified. Phylogenetically considered younger than the first. Allows the body to perceive more subtle stimuli, evaluate their degree, quality, localization, nature, and so on.

Location of receptors

This classification was proposed in 1906 by the English physiologist C. Sherrington. He proposed to divide all sensitivity into three categories:

Varieties of skin sensitivity

Classical physiology distinguishes the following types of skin sensitivity:

• Pain. Occurs under the influence of stimuli that are destructive in their strength and nature. She will talk about a direct danger to the body.
• Thermal (temperature) sensitivity. It allows us to determine hot, warm, cold, icy. Its greatest importance is for the reflex regulation of the body.
• Touch and pressure. These feelings are connected. Pressure, in fact, is a strong touch, so there are no special receptors for it. Experience (with the participation of vision, muscle feeling) allows you to accurately localize the area affected by the stimulus.

In some classifications, the varieties of skin sensitivity will be divided in this way:

• Pain.
• Feeling cold.
• Touch.
• Feeling warm.

Types of sensation thresholds

Now consider the classification of types of sensitivity thresholds:

• The absolute lower threshold of sensation. This is the smallest strength or magnitude of the stimulus at which its ability to cause nervous excitation in the analyzer is preserved, sufficient for the occurrence of one or another sensation.
• The absolute upper threshold of sensation. On the contrary, the maximum value, the strength of the stimulus, beyond which the body no longer perceives it.
• The threshold of discrimination (or the difference threshold of sensation) is the smallest difference in the intensity of two identical stimuli that a living organism can sense. Note that not every difference will be felt here. It needs to reach a certain size or strength.

Varieties of disorders

And now - types of disorders of sensitivity. The following stands out here:

• Anesthesia is the name given to the complete loss of any type of sensation. There is thermal (thermoanesthesia), tactile, pain (analgesia). There may be a loss of a sense of stereognosis, localization.
• Hypesthesia - this is the name of a decrease in sensitivity, a decrease in the intensity of certain sensations.
• Hyperesthesia is the opposite of the previous phenomenon. Here the patient has an increased sensitivity to certain stimuli.
• Hyperpathia - cases of perversion of sensitivity. The quality of sensation changes - point irritations crumble, some qualitative differences between the stimuli in the patient are erased. The sensation is painted in painful tones, it can be purely unpleasant. The aftereffect is also diagnosed - the sensation continues to remain after the cessation of the stimulus.
• Paresthesia - a person experiences any sensations without the presence of their stimuli. For example, "crawling", a sharp sensation - "as if thrown into a fever", burning, tingling, and so on.
• Polyesthesia - with such a violation, a single sensation will be perceived by the patient as multiple.
• Dysesthesia is a perverted perception of a particular stimulus. For example, touch feels like a blow, cold feels like heat.
• Synesthesia - a person will perceive the stimulus not only in the location of its direct impact, but also in a different zone.
• Allocheiria - a violation, something related to the previous one. The difference is that a person feels the impact of the stimulus not in the location of its impact, but in a symmetrical area of ​​the opposite part of the body.
• Thermalgia - cold, heat are painfully perceived by the patient.
• Dissociated sensory disorder - a case in which a certain sensation is disturbed, but all others are preserved.

Types of disorders

Types of sensory impairment can be divided into the following categories:

• Cortical type. This is a sensory disorder that will be observed on the opposite side of the body.
• Conductor type. Defeat of the conducting ways of sensitivity. Disorders will be found downward from the location of this lesion.
• Dissociated (segmental). It will be observed when the sensitive nuclei of the cranial nerve of the brain stems are damaged, as well as when the sensitive apparatus related to the spinal cord is damaged.
• Distal (polyneuric) type. Multiple lesions affecting peripheral nerves.
• peripheral type. It is characterized by damage to the peripheral nerves and their plexuses. Here there is a disorder of all kinds of sensations.

Sensitivity is a fairly broad phenomenon in understanding. Evidence of this is the large number of classifications that internally divide it into multiple groups. Also today, a variety of types of sensitivity disorders have been established, the gradation of which is associated with the localization of the lesion, the manifestation of sensations in the patient.

Observing creative personalities, it is impossible not to note their increased sensitivity. Sensitivity gives rise to emotional experiences, it gives rise to a storm of emotions, it is she who allows the artist to penetrate the secrets of the world and show their reflection in his works.

In the scientific literature, such a subtle structure of the soul is called sensitivity.

Sensitivity- a personality trait, expressed in increased sensitivity and vulnerability, self-doubt, increased conscientiousness and a tendency to doubt, fixation on one's experiences.
Big Medical Dictionary

Our feelings are the most important and complex aspect of spiritual life. These are not just fleeting sensations. This is the experience gained through our observation, mindfulness and receptivity. Sensitivity to art, objects around us, people with whom we communicate, undoubtedly enriches our inner world, making us spiritually filled and open.

• Sensitivity is a bright emotion that paints our life in bright colors.
• Sensitivity is empathy and empathy.
• Sensitivity is the ability to perceive not so much rationally as emotionally.
• Sensitivity is the path to aesthetic pleasure.

Sensitivity Benefits

• Thanks to sensitivity, we comprehend the essence of what is happening to us.
• Thanks to sensitivity, we enrich our inner world and have the opportunity to build inner harmony.
• Sensitivity leads to the creation of unique and unforgettable works of art, as they come from the very depths of the soul.
• Our sensitivity allows aesthetic taste and artistic experiences to manifest.

Manifestations of sensitivity in everyday life

Sensitivity in everyday life can manifest itself in completely different situations, and often it can cause even greater virtues.

• A bright, hysterical performance by an actor or music rich in many emotional nuances make it possible for our sensitivity to manifest itself.
• Sensitivity, coupled with imaginative thinking, push many of us to express our experiences through art - poetry, painting, music.
• We show our sensitivity by empathizing with other people - close or unfamiliar. A sensitive person can always easily understand another person and share his emotions.
• It is sensitivity that makes us compassionate and sacrifice our time, means, and perhaps even our lives for other people.

How to develop sensitivity

Of course, we will talk about balance and the golden mean. Hypersensitivity implies too active rethinking of what is happening around. In a world full of stress, upheaval and selfishness, over-sensitivity can threaten our inner harmony. Therefore, cultivating sensitivity in oneself, it is necessary to find a philosophical approach to life.

It is best to develop sensitivity with the help of works of art - painting, music, literature. Try to understand the hero of the work, transfer his feelings to yourself and imagine how you would feel if you were in a similar situation. In the world classical literature the actions of the characters are often given a detailed explanation, so they can be used as a "practical guide" for a detailed analysis of the emotions of other people.

Be more attentive to the people around you. During a conversation with them, try to understand with the help of questions why they acted one way or another, how they felt at that moment.

Sensitivity is not easy to develop, but it will help you more easily find a common language with other people and build your relationship with them on a completely different, higher level.

Golden mean

Callousness

Sensitivity

Over-sensitivity

Popular expressions about sensitivity

To feel is not the same as to understand. - A.N. Afinogenov - Feelings are the brightest part of our life. - Balzac - You can be the master of your actions, but in feelings we are not free. - G. Flaubert - Feeling is the eve of the appearance of thought. - I.N. Pevtsov - You can feel strongly, vividly and fieryly and at the same time not be able to express your feelings. - V.G. Belinsky - Esquivel Laura / The Book of Feelings How and why is a feeling born and dying? Can it be expressed in words? Is there a way to overcome the terrible evil of our time - depression? To make the world around you happier? Find inner harmony? Here are just a few of the many questions that the peculiar Mexican writer ponders. And her answers are amazingly unexpected. Alexander Berzin / Developing Balanced Sensitivity: Practical Buddhist Exercises for Daily Life Achieving emotional balance or maintaining healthy relationships is never easy. However, for various reasons, we further complicate these problems. These problems include lack of sensitivity or insensitivity in some situations and disproportionate sensitivity or overreaction in others. The author, adapting the Buddha's methods for self-improvement to modern Western conditions, considers these problems in accordance with the peculiarities of Western cultural characteristics.

When the words " hypersensitivity», « sensitive person", and even the term that has already become commonplace sounds - HSP (highly sensitive people), it becomes immediately clear we are talking about something that goes beyond the average, some statistical majority.

Many, having heard hypersensitivity" And " sensitive person", imagine a kind of muslin young lady, regardless of her real gender, who just faints" from an excess of feelings.

Someone thinks that all this is whims, and it is enough to “get together”, “stop winding yourself up”, and immediately this sensitivity will pass. All this, they say, from spoiled.

Still others, who are in the minority, believe that hypersensitivity- a gift, sensitive person, most likely talented and prone to creativity.

Let's try to figure out what HSP actually is, and, most importantly, how to live with it among those whose level of sensitivity is mostly lower.

Obviously, if there is an increased sensitivity, there is also a certain average, one might say - a statistical majority, something that many are accustomed to starting from as a norm.

Sensitivity in general is the ability of the human nervous system to perceive various stimuli coming from outside and respond to them. If you do not delve into the structure of the nervous system and physics, then in general we can say that human sensitivity exists within certain limits.

For example, human hearing recognizes sounds in the range of 20 - 20,000 hertz, or light human sensitivity is in the range of 380 - 760 nm, but everything that is inside these frames has very individual shades.

For example, to one person, the conversation of neighbors behind the wall will seem like a light, barely noticeable noise. Others won't hear anything at all. Third, every word will be heard. So it can be with color and with other sensations - taste, smells, touch. So it can be with the sensation of pain - any physician will tell you that the pain threshold in a person is individual.

At the same time, the researchers note that the population of the earth by about 10% - hsf highly sensitive people. The rest have the same average sensitivity, which is usually perceived as the norm. Rarely, there are cases of complete or partial loss of sensitivity, which are mainly associated with diseases of the central nervous system or with severe psychological shocks.

Why is that? Here, scientists so far agree that hypersensitivity is an innate characteristic. How is it defined hereditary factors- it is difficult to say, because in some cases it is possible to observe the appearance of children with high sensitivity in the family of parents with average indicators.

True, no one will say for sure whether at least one of the child's parents really did not have hypersensitivity, or whether he simply actively suppressed it and skillfully hid it. There is not much research on this topic yet, but so far there are a few obvious signs of HHL.

HSP signs

Physical

This is the very case when the conversation of the neighbors behind the wall seems loud and distinct to you, unlike the others. You are annoyed by pungent odors, too bright light, you are susceptible to light touches, distinguish the slightest shades of taste, temperature, your body reacts quite noticeably to many interventions - drugs, caffeine, other psychoactive and stimulant substances, you have a lower pain threshold (pain comes earlier , from less visible stimuli than for most).

emotional

You have an increased sense of empathy, you are quite easily imbued with the situation of another person and easily “pick up” his emotions, it is easy for you to feel the state of the people around you, sometimes - regardless of your desire, you easily feel the atmosphere of some place, you are more receptive to art, you are able to experience strong emotions from “little things”.

intellectual

You carefully consider and weigh your words, any incoming information, you tend to reflect on it, you have increased attention to details, nuances (for example, you notice grammatical errors and typos, are susceptible to all sorts of carelessness, negligence in the surrounding space, which others may not notice at all for a long time), you are able to see many meanings in any external object.

This division, of course, is conditional - it is impossible to disassemble a person, like a mechanism, into parts, therefore, of course, everything is connected. But a sensitive person is not necessarily one who has all the senses "at the limit."

For example, he may have very high auditory and visual sensitivity, while he may show a normal pain threshold, or, say, not be highly sensitive to drugs. Or, let's say a person has high empathy, but he is not inclined to go deep into intellectual meanings.

Therefore, now we will talk about what nuances high sensitivity has, touching on common myths about sensitivity, talk about how this is related to other aspects of a person’s psychological characteristics - for example, introversion / extraversion, psychotype, temperament, degree of neuroticism, and maybe whether it be a symptom of some other condition, disease.

In general, hypersensitivity is not an innate characteristic of a person, but a consequence of certain conditions of the body. For example, sensitivity may increase if there is chronic sleep deprivation, constant fatigue, severe stress (as, however, a partial decrease in sensitivity can also be a reaction to stress, as if “freezing” in the presence of very strong and indigestible feelings).

Hypersensitivity may accompany some mental disorders and somatic diseases especially related to the CNS. But this mention is only so that you can decide for yourself whether your characteristic is permanent or temporary. Here we will talk mainly about those whose hypersensitivity is constant, you yourself remember yourself like this all your life, and you have not observed any other serious deviations in the field of health.

So far, I have not come across studies in which it would be clearly possible to trace which psychotypes are more often associated with increased sensitivity. However, our own practice gives enough reason to assert that hypersensitivity is neither the fifth type of temperament, nor any special psychotype, HSPs are found among representatives of different temperaments and psychotypes.

It can be said that some psychotypes appear among HSPs more often than others, but a clear correlation has not yet been traced. That is, a sensitive person can be born like that with any other character traits.

Many people assume that HSPs tend to be more introverted. This is logically understandable: a sensitive person needs more time to recover from contact with the outside world, because external stimuli act on him more than others, and he needs to disconnect from strong stimulation more often.

But I have also met extroverts among HSPs. Yes, such a person also needed to retire from time to time, to have time to recover, but the focus of attention of such a person was still directed to the outside world, and not to the inner one, like introverts.

With temperament, too, it is not possible to establish a clear connection. It would be logical to assume that HSPs are more suited to people with fast arousal and slow deceleration, in other words, they are easy to turn on but difficult to calm down (which are melancholics), but this is more like speculation about how a sensitive person should be, or could be in the opinion of the middle majority, not on reality.

And the logic can be completely different. Sometimes heightened sensitivity fits, say, into a phlegmatic person who does not look like a sensitive person at all. However, the phlegmatic temperament creates good protection for the carrier of subtle sensitivity, and it even blossoms inside him in a lush color, since outwardly she is little threatened.

In general, here we can say that hypersensitivity is not directly related to specific features of the psychotype, temperament or focus of attention, it exists as a separate psychophysiological characteristic that is built into other personality parameters.

But a person not only experiences feelings, he also interprets them. For example, the fact that he is more responsive to the people around him and their condition, needs more rest from this stimulation, he can interpret in different ways.

He can calmly say to himself: “Yes, it’s already too much for me today, I want to be in silence” - and calmly retire. Or he can start to wind himself up in the spirit of “all people are like people, but I’m not like that, probably something is wrong with me, since everything starts to annoy me so quickly ....”

Often, HSPs are confused with people who are prone to anxiety, suspiciousness and thinking on this basis for others. But heightened sensitivity and anxiety reinforced by fantasies are two different things.

A sensitive person will be able to capture the real state of the other person - for example, he will be able to feel that his boss has already entered the office irritated and tense, and further separation of employees only followed from his initial state. Therefore, a sensitive person is unlikely to take it personally. However, he may be hurt for another reason - too loud, too bright, too hard.

But an anxious person just may not feel the real state of the authorities, he is mainly occupied with his experiences, and therefore he will easily attribute the dressing to himself alone, and then he will worry for days about his alleged worthlessness and failure.

It is also easy to confuse people who are able to loudly and vividly demonstrate their feelings (it is not at all necessary that the feelings are sincere, and that they generally exist) with HSP. But demonstration and real feeling are very different things. HSPs are just not in a hurry to share their feelings so quickly, much less so loudly: the demonstration attracts attention even more, makes them digest a lot more external stimuli, and further exacerbates the fatigue from their own reactions.

And here it is very logical to mention a few common myths about sensitivity.

HSP: myths and reality

In fact, rather the opposite. Among them, many strong people who control their feelings much better at times than the representatives of the average majority.

Why? Yes, because from childhood, such a child understands that he is different from others, that his feelings are sometimes not taken seriously by others. Parents and other adults are not always ready to take feelings (and even more so - so subtle!) into account and sometimes even declare them abnormal.

Naturally, in response to this, the child develops defenses. And one of them is the formation of the skill of tracking and controlling your emotions. Yes, sometimes this leads to sad options - a habit is formed to suppress their feelings, low self-esteem, a feeling of constant misunderstanding and rejection.

But increased sensitivity also gives its bonus, especially in the presence of high intelligence: after all, the mass of feelings inaccessible to others is a mass of information, this is a more complete and rich knowledge of the world, this is a more subtle insight into the essence of human motives and relationships, and as a result - a more effective strategy of action, and in the long run - a more comfortable place in life.

In general, HSPs are less likely to act rashly “on emotions”, they are more likely to think about the nuances of their reactions and behavior, they can more effectively cope with difficult life situations, if only because life taught them very early to cope with their feelings in world less sensitive.

Myth: A sensitive person is open, kind, and therefore very vulnerable.

This is also from the realm of fantasy. HSPs tend to keep their feelings away from others most of the time, or at least that's what experience teaches them. Not every closed person belongs to the HSP category, but we can say that among the HSPs there are many who are considered to be closed. And, especially having the experience of different perceptions of themselves, HSPs are very selective in communication.

The capacity for empathy, which HSPs certainly have to a large extent, is not a reason for kindness, let alone naivety. The experience of subtle feeling can be applied in many ways, but think about it: subtle sensitivity involves feeling all spectrums.

And this means that a sensitive person feels not only the wonderful feelings of people filled with positive. In principle, there are not enough of them in the world, to put it mildly. And it turns out that the main content of empathy is a very different, and far from always positive state of people.

What conclusions can HSPs draw from this? - yes, whatever. You can find yourself in a helping profession in order to attach this empathy, to give it a place. And you can hate the whole human race for the constant violation of boundaries and for that very joyless inner content. And for example, to become a charming villain like Hannibal Lecter, who, in addition to killing, enjoys delicate dishes from their liver or brain, decorates the house with exquisite paintings and listens to rare performances of the opera.

Therefore, in terms of moral guidelines, HSPs can be at any pole of society, and sensitivity will only impart certain shades to their actions, but it does not in any way limit their choice in terms of their own ethics.

Myth: Sensitive people are talented and smart

This is partly true, of course, because hypersensitivity itself is an indication for certain types of activities in which it is needed - many areas of art and science (especially where intuition matters), in general, a creative environment that helps professions - psychologists, doctors, social workers.

But at the same time, increased sensitivity also imposes certain restrictions - for example, a sensitive person cannot always work in the conditions in which the majority can work. And sometimes it becomes an obstacle to career development in the standard way accepted in society and a particular profession.

I have known people who have a high sensitivity combined with low intelligence. This is perhaps the most difficult of all HSPs, because they do not have enough resources to realize their uniqueness, while they also do not always succeed in fully integrating into the world of ordinary people.

In summary, HSPs are simply people with a distinct characteristic that goes along with different personality traits. Of course, increased sensitivity to one degree or another leaves an imprint on the formation of a psychotype, and on interaction with temperament, and on behavioral habits.

And this is certainly a variant of the norm, which, however, differs from the majority and creates certain problems for such people. And in the next part of the article, we will dwell in more detail on the development of a sensitive child and talk about what parents should do, whose child is just like that: “ Sensitive child: features of the development of a sensitive person».

Sensitivity I

the ability of the organism to perceive various stimuli emanating from the external and internal environment, and to respond to them.

Ch. is based on the processes of reception, the biological significance of which lies in the perception of stimuli acting on them, their transformation into excitation processes (Excitation) , which are the source of the corresponding sensations (pain, temperature, light, auditory, etc.). Subjectively experienced appears with threshold stimulation of certain receptors (Receptors) . In those cases when the incoming receptors in the c.n.s. below the threshold of sensation, it does not cause this or that sensation, however, it can lead to certain reflex reactions of the body (vegetative-vascular, etc.).

For understanding the physiological mechanisms of Ch., the teachings of I.P. Pavlova about analyzers (Analyzers) . As a result of the activity of all parts of the analyzer, a subtle and synthesis of stimuli acting on stimuli is carried out. In this case, not only the transmission of impulses from receptors to the central analyzer occurs, but also a complex process of reverse (efferent) regulation of sensitive perception (see Self-regulation of physiological functions) . The excitability of the receptor apparatus is determined both by the absolute intensity of stimulation, and by the number of simultaneously stimulated receptors or by the quality of their repeated irritations - the law of summation of receptor irritations. the excitability of the receptor depends on the influence of the central nervous system. and sympathetic innervation.

Sensory impulses from the peripheral receptor apparatus reach the cerebral cortex along specific pathways and through non-specific conduction systems of the reticular formation (Reticular formation) Non-specific afferent impulses travel along the spinoreticular pathway, which at the level of the brainstem (Brainstem) has connections with cells of the reticular formation . The activating and inhibitory systems of the reticular formation (see Functional systems) carry out the regulation of afferent impulses, participate in the selection of information coming from the periphery to the higher parts of the Ch. system, passing some impulses and blocking others.

There are general and special Ch. General Ch. is divided into exteroceptive, proprioceptive and interoceptive. Exteroceptive (superficial, skin) include pain, temperature (thermal and cold) and tactile Ch. () with their varieties (for example, electrocutaneous - sensations caused by various types of electric current; feeling of moisture - hygroesthesia , it is based on a combination of tactile sensation with temperature; a feeling of itching is a variant of tactile Ch., etc.).

Proprioceptive (deep) Ch. - bathiesthesia includes muscular-articular Ch. (a sense of the position of the body and its parts in space), vibration (), pressure (). To interoceptive (vegetative-visceral) is Ch., associated with the receptor apparatus in the internal organs and blood vessels. There are also complex types of sensitivity: two-dimensional-spatial feeling, localization, discriminatory sensitivity, stereognosis, etc.

The English neurologist Ged (N. Head) proposed to divide the general sensitivity into protopathic and epicritical. Protopathic Ch. is phylogenetically older, associated with the thalamus, and serves to perceive nociceptive stimuli that threaten the body with tissue destruction or even death (for example, strong pain stimuli, sudden temperature effects, etc.). Epicritical Ch., phylogenetically younger, is not associated with the perception of damaging effects. It enables the body to navigate in the environment, to perceive weak stimuli, to which the body can respond with a choice reaction (an arbitrary motor act). Epicritical Ch. include tactile, low temperature fluctuations (from 27 to 35 °), irritation, their difference (discrimination), and muscular-articular feeling. Decrease or function of the epicritical Ch. leads to disinhibition of the function of the protopathic Ch. system and makes the perception of nociceptive irritations unusually strong. At the same time, pain and temperature stimuli are perceived as especially unpleasant, they become more diffuse, spilled and do not lend themselves to precise localization, which is indicated by the term "".

Special Ch. is associated with the function of the sense organs. It includes Vision , Hearing , Smell , Taste , Body balance . Taste Ch. is associated with contact receptors, other types - with distant receptors.

Ch.'s differentiation is connected with structural and physiological features of a peripheral sensitive neuron - its receptor and a dendrite. Normal for 1 cm 2 skin has an average of 100-200 pain, 20-25 tactile, 12-15 cold and 1-2 heat receptors. Peripheral sensory nerve fibers (dendrites of cells of the spinal ganglion, trigeminal ganglion, jugular node etc.) conduct excitation impulses at different speeds depending on the thickness of their myelin layer. Group A fibers, covered with a thick layer of myelin, conduct an impulse at a speed of 12-120 m/s; group B fibers, which have a thin myelin layer, drive impulses at a speed of 3-14 m/s; group C fibers - unmyelinated (have only one) - at a speed of 1-2 m/s. Group A fibers serve to conduct impulses of tactile and deep Ch., but they can also conduct pain stimuli. Group B fibers conduct pain and tactile stimuli. Group C fibers are conductors of mainly pain stimuli.

The bodies of the first neurons of all types of Ch. are located in the spinal ganglia ( rice. 1 ) and in the nodes of sensory cranial nerves (Cranial nerves) . The axons of these neurons, as part of the posterior roots of the spinal nerves and the sensory roots of the corresponding cranial nerves, also enter the brain stem, forming two groups of fibers. Short fibers end in a synapse at the cells dorsal horn spinal cord(their counterpart in the brainstem is the descending spinal tract trigeminal nerve), which are the second sensitive neuron. The axons of most of these neurons, having risen by 2-3 segments, pass through the anterior white commissure to the opposite side of the spinal cord and go up as part of the lateral spinothalamic tract, ending in a synapse at cells of specific ventrolateral nuclei of the thalamus. These fibers carry pain and temperature pulses. Another part of the fibers of the spinothalamic pathway, passing through the simplest types of tactile sensitivity (, hair sensitivity, etc.), is located in the anterior funiculus of the spinal cord and makes up the anterior spinothalamic tract, which also reaches the thalamus. cells of the nuclei of the thalamus (third sensitive neurons) axons, forming the posterior third of the posterior thigh of the inner capsule, reach the sensitive neurons of the cerebral cortex (cerebral cortex) ( posterior central and parietal).

A group of long fibers from the posterior root passes uninterruptedly in the same direction, forming thin and wedge-shaped bundles. As part of these bundles, axons, without crossing, rise to the medulla oblongata, where they end in nuclei of the same name - in the thin and wedge-shaped nuclei. Thin (Goll) contains fibers that conduct Ch. from the lower half of the body, wedge-shaped (Burdaha) - from the upper half of the body. The axons of the cells of the thin and sphenoid nuclei pass at the level of the medulla oblongata to the opposite side - the upper sensitive medial loops. After this decussation in the suture, the fibers of the medial loop go up in the posterior part (tire) of the pons and midbrain and, together with the fibers of the spinothalamic tract, approach the ventrolateral nucleus of the thalamus. Fibers from the thin nucleus approach the cells located laterally, and from the sphenoid nucleus - to more medial groups of cells. The axons of sensitive cells of the nuclei of the trigeminal nerve also fit here. neurons of the thalamic nuclei, axons pass through the posterior third of the posterior thigh of the internal capsule and, ending at the cells of the cortex of the postcentral gyrus (fields 1, 2, 3), the upper parietal lobule (fields 5 and 7) of the cerebral hemispheres. These long fibers carry out muscular-articular, vibrational, complex types of tactile, two-dimensional-spatial, discriminatory Ch., feelings of pressure, stereognosis - from the receptors of the same half of the body to the medulla oblongata. Above the medulla oblongata, they reconnect with conductors of pain and temperature sensitivity of the corresponding side of the body.

Research methods sensitivity is divided into subjective and objective. Subjective methods are based on the psychophysiological study of sensation (absolute and differential thresholds of sensitivity). Clinical Study H. (see Examination of the patient , neurological examination) should be carried out in a warm and quiet room. In order to better focus on the perception and analysis of sensations, he should lie with his eyes closed. The results of Ch.'s research depend on the patient's reaction, his attention, the safety of consciousness, etc.

Pain sensitivity is examined by a pin prick or other sharp object; temperature - by touching the skin with test tubes filled with cool (not higher than 25 °) and hot (40-50 °) water. More accurately, temperature Ch. can be examined using a thermoesthesiometer, and pain - with a Rudzit algesimeter. The threshold characteristic of pain and tactile sensitivity can be obtained by examining graduated bristles and hairs using the Frey method. Tactile Ch. is examined by lightly touching the skin with a brush, pieces of cotton wool, soft paper, etc. Discriminatory Ch. is examined with Weber's compass. Normally, two separate irritations on the palmar surface of the fingers are perceived when one is removed from the other by 2 mm, on the palmar surface of the hand, this distance reaches 6-10 mm, on the forearm and dorsum of the foot - 40 mm, and on the back and hips - 65-67 mm.

The muscular-articular feeling is examined in the position of the patient lying down, always with his eyes closed. produces an unsharp passive in individual small or large joints - extension, adduction, etc. The subject must determine the direction, volume and these movements. You can use a kinesthesiometer. With a pronounced violation of the muscular-articular feeling, a sensitive (Ataxia) .

The feeling of pressure is determined by distinguishing pressure from a light touch, and also by detecting the difference in the degree of pressure applied. The study is performed using a baresthesiometer - a spring apparatus with a pressure intensity scale expressed in grams. Normally, it distinguishes between an increase or decrease in pressure on the arm by 1/10 - 1/20 of the original pressure.

Vibrating frequency is examined with a tuning fork 64-128 Hz. The leg of a sounding tuning fork is placed on protrusions (ankles, forearms, iliac crest, etc.). Normal vibration at the ankles lasts 8-10 With, on the forearm - 11-12 With.

The ability to recognize two-dimensional stimuli is examined by asking the patient to determine, with his eyes closed, the numbers, letters and figures that he draws with a pencil or the blunt end of a pin on the skin of the subject.

The stereognostic sense is defined by the ability to recognize coins, a pencil, a key, etc. when touched with closed eyes. The subject evaluates the shape, consistency, temperature, surfaces, approximate mass and other qualities of the object. The complex act of stereognosis is associated with the associative activity of the brain. When defeated general types sensitivity is impossible - secondary (pseudoastereognosis). Primary happens with a disorder of higher brain (cortical) functions - gnosis (see Agnosia) .

Sensitivity disorders often seen with various diseases nervous system and, as a rule, are used to clarify the tonic diagnosis, as well as to control the dynamics of the pathological process under the influence of the patient's treatment. Distinguish between quantitative and qualitative violations of Ch. Quantitative are a decrease in the intensity of sensation - or a complete loss of Ch. -. This applies to all types of Ch., analgesia - a decrease or absence of pain Ch., thermoanesthesia - a decrease or absence of temperature Ch., topohypesthesia, topanesthesia - a decrease or loss of localization of irritations, etc. An increase in Ch. - is associated with a decrease in the threshold of perception of one or another irritation . Qualitative disturbances of Ch. include a perversion of the perception of external stimuli, for example: the occurrence of a sensation of pain during cold or thermal irritation, a sensation of a larger size of a palpated object - macroesthesia, a sensation of many objects instead of one - polyesthesia, a sensation of pain in another zone in relation to the injection site - synalgia, sensation of irritation not in the place of its application - alloesthesia, sensation of irritation in a symmetrical area on the other hand -, inadequate perception of various irritations -. Ch. represents a special form of qualitative change - a kind of painful perception of various sharp irritations. With hyperpathy, excitability increases (light irritations are perceived in the hyperpathic zone less clearly than normal, and intense irritations are sharply painful, extremely unpleasant, painful), irritations are poorly localized by the patient, and they are noted for a long time.

Ch.'s disorders include paresthesias - various sensations not associated with any external influence - goosebumps, numbness, tingling, stiffness of skin areas, pain in the hair roots (trichalgia), a feeling of skin moisture, drops of liquid on it (). Especially often, a variety of paresthesias are observed with dorsal tabes (Tapes dorsalis) , funicular myelosis (Funicular myelosis) and other diseases of the nervous system, in which the posterior cords of the spinal cord and posterior roots are involved in the process.

Depending on the localization of the pathological process in the nervous system, various types of Ch disorders are observed. different types Ch. (increase or decrease in the threshold of pain, tactile and other types of Ch.).

When a sensory nerve is damaged, two zones of disturbance are detected: anesthesia in the zone of autonomic innervation of this nerve and hypesthesia with hyperpathy in the zone of mixed innervation (overlapping zones of innervation with another nerve). Mismatch of violation zones is noted various kinds Ch.: the largest surface is occupied by the area with violation of temperature Ch., then tactile, and least of all - the area of ​​violation of pain Ch. °) and low (below 20°), injections are perceived as extremely unpleasant, diffuse, long-lasting sensations. Later (about 1 year later), tactile sensitivity is restored, the ability to distinguish between temperatures from 26 to 37 °, at the same time, the localization error and increased pain stimuli disappear (Ged-Sherren's law). With damage to the peripheral nerve, all types of sensitivity are disturbed (see Neuritis) . For multiple symmetrical lesions of the peripheral nerves of the extremities (see Polyneuropathies) characteristic is a violation of all types of Ch. according to the polyneuritic or distal type - in the form of gloves on the hands and stockings (socks) on the legs ( rice. 2 ).

With damage to the posterior roots, disorders of all types of Ch. are localized in the corresponding dermatome ( rice. 3 ). With a viral lesion of the spinal node and sensitive root, paresthesia and hypesthesia are combined with herpetic eruptions in the same dermatome (see Ganglionitis) .

With the defeat of the entire diameter of the spinal cord, a conductor of all types develops with an upper border, which indicates the level of the spinal cord ( rice. 4 ). With the localization of the pathological focus above the cervical thickening of the spinal cord, the upper and lower extremities, the trunk appear. This is combined with central tetraparesis, dysfunction of the pelvic organs (see spinal cord) . The pathological focus at the level of the upper thoracic segments is manifested by anesthesia on the lower extremities, central lower paraparesis, and dysfunction of the pelvic organs. In case of damage to the lumbar segments of the spinal cord, conduction anesthesia captures lower limbs and anogenital area.

The pathology of the thalamus causes Dejerine-Roussy, in which all types of Ch. decrease or disappear on the half of the body opposite to the focus, sensitive and moderate develop in the same limbs, contralateral hemianopsia . Characteristic of the defeat of the thalamus is hyperpathy and central against the background of hypesthesia on the entire half of the body. Thalamic pain is always very intense, diffuse, burning and resistant to analgesics.

With the defeat of the posterior thigh of the internal capsule, the so-called capsular one develops on the half of the body opposite to the focus. It is characterized by more pronounced Ch.'s disorders in the distal extremities, especially on the arm.

A pathological focus in the radiant crown or cerebral cortex ( postcentral) causes monoanesthesia on the face or only on the arm, or only on the leg (depending on the location of the focus and in accordance with the somatotopic representation of sensitivity). with cortical pathological foci, it is more pronounced in the distal parts of the limb, and the muscular-articular feeling and vibrational frequency are more disturbed than the superficial frequency.

When the pathological process is localized in the parasagittal region, both paracentral lobules are simultaneously disturbed and sensitivity is impaired on both feet.

Irritation of the sensitive zone of the cerebral cortex (with, cicatricial adhesive process, etc.) leads to Jacksonian sensitive seizures (see Jacksonian epilepsy) : paresthesias in the face, arm or leg, lasting from a few seconds to minutes without a change in consciousness. With damage to the parietal lobe, more complex types of violation of Ch. develop, a weakening of the ability to discriminate, two-dimensional-spatial Ch., stereognosis, to determine spatial relationships (topognost).

Bibliography: Krol M.B. and Fedorova E.A. The main neuropathological syndromes, M,. 1966; Skoromets A.A. diseases of the nervous system, L., 1989.

Rice. 4. Scheme of conduction spinal paraanesthesia with an upper limit on Th X .

Rice. 1. Scheme of conductors of superficial (A) and deep (B) sensitivity: 1 - cell of the spinal ganglion; 2 - cell of the posterior horn of the spinal cord; 3 - spinothalamic tract; 4 - ; 5 - postcentral gyrus (zone of the leg); 6 - cell of the spinal ganglion; 7 - Gaulle's bundle; 8 - Gaulle's beam core; 9 - bulbotalamic tract ().

II Sensitivity

the ability of the body to perceive irritations emanating from the environment or from its own tissues and organs.

Visceral sensitivity(s. visceralis) - Ch. to irritations acting on internal organs.

Sensitivity of taste(s. gustatoria) - Ch. to chemical action, realized by the appearance of a sensation of taste of the active substance.

Sensitivity deep(s. profunda) - see Proprioceptive sensitivity.

Directional sensitivity- Ch. to some properties of the environment, which is realized by spatial orientation, the allocation of a certain direction in it.

Sensitivity discrimination(s. discriminativa) - Ch., which consists in the ability to distinguish between two simultaneous identical irritations of different localization, for example, in different areas.

Sensitivity differential(s. differentialis; Ch. difference) - a variety of Ch., which consists in the ability to perceive a change in the intensity of irritation.

Sensitivity interoceptive(s. interoceptiva) - H. to irritations emanating from the internal environment of tissues and organs.

Skin sensitivity(s. cutanea) - Ch. to irritation of various (tactile, temperature, pain) skin receptors.

Nociceptive sensitivity(s. nociceptiva) - see Pain sensitivity.

Olfactory sensitivity(s. olfactoria) - Ch. to chemical effects, realized by the appearance of the smell of the influencing substance.

Surface sensitivity(s. superficialis) - see Sensitivity exteroceptive.

Sensitivity proprioceptive(s. proprioceptiva; synonym: deep sensitivity) - C. to irritation of muscles, tendons, ligaments and other elements of the joints.

Protopathic sensitivity(s. protopathica; Greek prōtos first, primary + pathos feeling, suffering,) is a phylogenetically ancient Ch., characterized by limited possibilities for differentiating stimuli according to their modality, intensity and localization.

Sensitivity difference- see Differential sensitivity.

light sensitivity(s. visualis) - H. to the effects of visible radiation.

Sensitivity is difficult(s. composita) - Ch., based on the integration of the activity of receptors of various modalities.

Hearing sensitivity(s. auditiva) - H. to the effects of sound.

temperature sensitivity(s. thermaesthetica) - Ch. to a change in ambient temperature.

Sensitivity exteroceptive(s. exteroceptiva; syn. Ch. superficial) - Ch. to irritations emanating from the environment.

Electrodermal sensitivity(s. electrocutanea) - a kind of skin Ch., which consists in the ability to perceive when exposed to electric current.