Sensitivity as a quality of a person is the ability to feel, express one's emotions, hear one's own voice of the soul, subtly capture the shades of the mood of others, understand and empathize with their feelings, perceive the beauty of the world, nature, works of art with piercing sharpness.

Once the great Teacher Abu Ali Ibn Sina told his students about the need to be observant and vigilant in life. He said that the human senses can be trained in the same way as thought and muscles. - For example, you enter a room, and your sensitivity immediately captures the most important details. At that moment, the Master was informed that they had come to him and were asking him to come out. Ibn Sina said to his students: - Sit down, I'll be right back. And went to the visitors. The disciples decided to test their Master's sensitivity. Putting a blank sheet of paper under the mat on which he sat, they eagerly awaited his return: would he feel any change? When Ibn Sina returned and sat down in his place, he immediately read some kind of conspiracy in the cunningly narrowed eyes of his students. Carefully examining his students, he said: - Probably, either I grew up, or the ceiling became lower ...

Sensitivity is the increased vulnerability of the heart. In physiology, it is interpreted as the ability to perceive irritations from the external environment and from one's own tissues. Human skin reacts to irritation caused by the activation of certain receptors. The main types of sensitivity: tactile, pain, temperature, muscular-articular, vibration. Depending on sensations, the brain receives the necessary information about the world around us. There is such an anecdote. The doctor checks the sensitivity. - Doctor, doctor! And why are you groping me? — I check if the sensitivity is preserved. — Do I have something? - I do not have. We are not interested in physiological sensitivity, but in stable, clearly manifested personality traits associated with vividly experienced impressions, with the perception of one's inner and outer world through the heart.

Sensitivity is the ability to know oneself. Women are six times more sensitive than men. Their mind is located in close proximity to the senses, while in men it is close to the mind. In this difference lies the secret of almost all the nuances of the relationship between the sexes. This is where many of the features of male and female behavior come from.

Male nature is responsibility, patronage and care for a woman and children. Coming into contact with the harsh realities of the outside world for most of the day, proving every day that he owes him money, a man sometimes becomes an insensitive idol. Sensitive stronger sex - sounds like nonsense, nonsense. But life does not like extremes. In order to perceive the world in all its rich palette of colors, a man also needs a certain amount of sensitivity. Who can help him learn to hear the voice of his own heart, to capture the nuances of a woman's mood, to express his feelings more emotionally? He himself cannot reproduce sensitivity in himself. Only a woman with her sensitive heart, softness, tenderness and flexibility can kindle a warming fire of sensitivity in him. Man and woman balance each other. A man protects a woman from excessive emotionality, and she protects him from coldness and lack of emotions. Women with extraordinary ease determine the mindset of men. He is still climbing the stairs, and the experienced wife already feels in what mood he is. Men, by and large, envy this ability. They realize that in order to solve many problems, they would not be hindered by a subtle feeling of the mood of their boss, partners, opponents or subordinates.

A man, if he has not learned to feel himself, runs the risk of becoming an object of manipulation, is in danger of doing not what he wants himself, but what the manipulators expect from him. There is such a parable. - Today is a terrible day. Everything, as if by agreement, makes me nervous, angry and annoyed, - one person said to another. - And do not say, - his familiar musician answered, - I have similar problems. Today, as luck would have it, everyone touches my violin. Because of this, she gets upset, after which it is impossible to play on her. “So why don’t you set it up properly and hide it in a case so that inept hands don’t upset it and make dissonant sounds that cut into your sensitive hearing?” Don't you think that only you are to blame for this? Why do you let whoever cares to play your instrument? And if you don't like what they play, wouldn't it be better to hide it or play what you like yourself? - I see, dear friend, that you are well versed in music. So why don't you apply this knowledge to your "tool" yourself? Why don’t you properly set up your consciousness, take it into your own hands and start “playing” what you yourself like, instead of letting anyone “play” whatever they please on the sensitive strings of your soul? Why, instead of learning to play a song of love, patience and forgiveness, do you play a mourning march of resentment and a funeral march of anger? Don't you think that it's not the people who get on your nerves that are to blame, but you yourself? Know that you can choose whether to play yourself or let others play. The choice is yours!

Unlike sensibility, which sees and turns on lust, sensibility sees and simply feels with the heart. Sensitivity loves to talk about experiences and emotions, showing a sincere reaction to them. She does not need to practice eloquence. It is enough to look at her face and it immediately becomes clear that we are facing a person who knows how to deeply feel and empathize with the state of another. A sensitive person is usually benevolent, quiet, timid and touchy. He lacks energy, activity and initiative. Sensitive people rarely occupy leadership positions because they can be good performers, but when decisions need to be made under conditions of relative risk and accountability for these decisions, they most often fold.

Karamzin wrote: “A sensitive heart is a rich source of ideas: if reason and taste help it, then success is not in doubt and a celebrity awaits the writer.” A vivid example of a sensitive person was the great and unique landscape painter I.I. Levitan. Levitan's comrade, Mikhail Nesterov, in his book of memoirs "Old Days", recalled that the young Levitan, having waited for the last tour of the school by the soldier Zemlyankin, nicknamed "Unclean Power", was left alone to while away the night in warmth, there was a long winter evening and a long night with so that in the morning, on an empty stomach, start the day with dreams of dearly beloved nature. A special, to the point of tears, love for nature and nervous sensitivity to its conditions were inherent in the future landscape painter from the very beginning. Relatives recalled how from an early age he loved to wander through the fields and forests, contemplate any sunset or sunrise for a long time, and when spring came, “he was completely transformed and fussed, worried, he was drawn to the city, where he ran away every time, like this given at least half an hour."

A.P. Chekhov wrote: “... Such amazing simplicity and clarity of motive, which Levitan has recently reached, no one has reached him, and I don’t know if anyone will come after.” The brilliant landscape painter died in 1900, at the time of flowering of his favorite phloxes. They were laid on his grave by young artists - those whom he taught to comprehend nature sensitively, deeply and penetratingly, so as to hear the "vegetation of grass."

Petr Kovalev 2013

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 irritations 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 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 non-specific pathways 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 the 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 organism to navigate in the environment, to perceive weak stimuli, to which the organism 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 the cells of the spinal node, trigeminal node, jugular node, etc.) conduct excitatory 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. one ) 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, enter the brainstem, forming two groups of fibers. Short fibers end in a synapse at the cells of the posterior horn of the spinal cord (their analogue in the brainstem is the descending spinal tract of the trigeminal nerve), which is 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 Ch. (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. With the defeat of general types of sensitivity, this is impossible - secondary (pseudoastereognosis). Primary happens with a disorder of higher brain (cortical) functions - gnosis (see Agnosia) .

Sensitivity disorders are often observed in various diseases of the 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 irritation, 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 less clearly in the zone of hyperpathy than normal, and intense irritations are sharply painful, extremely unpleasant, painful), irritations are poorly localized by the patient, they are noted for a long time.

Ch.'s disorders include paresthesia - 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 disorders of Ch. are observed. When the receptor apparatus is damaged, a local one is observed due to a decrease in the number of receptor points, as well as changes in the threshold characteristics of different 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 of innervation zones with another nerve). There is a discrepancy between the zones of violation of various types of Ch.: the largest surface is occupied by the area with violation of the temperature Ch., then the tactile one, and least of all - the area of ​​violation of the painful Ch. relatively high temperature (above 37 °) 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's - 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. When the lumbar segments of the spinal cord are affected, conduction anesthesia captures the lower limbs and the anogenital zone.

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, 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

Sensitivity is the ability of a living organism to respond to various kinds of stimuli emanating from the external or internal environment. The study of sensitivity occupies an important place in determining the state of the nervous system of the body. At the same time, the problem of sensitivity is of great theoretical and philosophical significance and is connected with the theory of knowledge. By means of the sensations underlying the sensitivity, arising as a result of exposure to various stimuli on the body, knowledge of the surrounding world occurs, which was formulated in the brilliant statements of V. I. Lenin, who emphasized that “... sensation is really a direct connection of consciousness with the outside world, is the transformation of the energy of external stimulus into a fact of consciousness. (V. I. Lenin, Collected works, ed. 5, vol. 18, p. 46.)

For understanding the physiological mechanisms of sensitivity, the doctrine of the analyzer is of particular importance (see), in which the peripheral section is distinguished - the receptor apparatus, the conductor and brain sections, mainly the cortical end of the analyzer. Sensitivity is based on the dynamic interaction of various parts of the system of one or another analyzer. In its peripheral final body, a so-called receptor (see), the impulse extending in TsNS originates.

The main biological significance of receptor devices lies in the fact that they are able to respond with the appearance of excitation under the action of stimuli, being a source of corresponding sensations - pain, tactile, temperature, etc. For the sensation to occur, it is necessary that the stimuli that set the receptor have sufficient intensity. The minimum force of irritation that can cause a sensation is called the threshold force, the threshold. The higher the intensity and the longer the duration of the stimulation, the faster the threshold is overcome, the more intense the sensation. The excitability of the receptor is determined not only by the absolute intensity of stimulation, but also by the number of simultaneously stimulated receptors or the quality of their repeated irritations - the law of summation of receptor irritations. On the other hand, the excitability of the receptor and its threshold also depend on the influence of the central nervous system, as well as on sympathetic innervation. Normally, the threshold height of different receptors is not the same.

For the correct and objective analysis of sensitive stimulation, including that part of it that has no equivalent in the form of sensation, the possibility of registering electrical potentials accompanying the appearance of impulses in the receptor apparatus in connection with the corresponding irritation is of great importance.

Receptors, depending on their location, are divided into somato- and visceroreceptors. The former include exteroreceptors, which are divided into distance receptors that perceive irritation at a distance (for example, visual, auditory, etc.), contact receptors that perceive irritation in direct contact with an external object and are located in the skin and mucous membranes, and proprioreceptors - in deep tissues ( muscles, tendons, joints), as well as in the ear labyrinths. Visceroreceptors are the final sensory apparatuses of various visceral organs, vessels, etc. Histological studies show the originality and complexity of the structure of the final sensory apparatuses. These features of the peripheral receptor apparatus served as starting points for the clinical classification of sensitivity.

At the heart of this classification, most authors note the quality, nature of the irritation (prick, heat, touch, etc.), the subjective sensations associated with this irritation (pain, etc.), the area of ​​​​impact of irritation (skin, muscles, etc.). Accordingly, separate types are distinguished 4.1. Skin, or exteroceptive, superficial sensitivity - pain, tactile, temperature (heat and cold). Varieties of these types of sensitivity: electrocutaneous - sensations caused by various types of electric current; the feeling of itching is a kind of tactile sensitivity; a sense of humidity - hygresthesia (it is based on a combination of tactile sensation with temperature). 2. Proprioceptive, deep, sensitivity - bathiesthesia. These include musculo-articular sensitivity or sensitivity of body position in space; vibration - pallesthesia; feeling of pressure - baresthesia. 3. Interoceptive, vegetative-visceral, covering the sensitivity of internal organs, blood vessels, etc. Separately, complex types of sensitivity are distinguished, where more complex analyzer processes predominate - discriminatory, two-dimensional-spatial, stereognosis. According to Geda's classification (see Geda zones), all sensitivity should be divided into protopathic, associated with the thalamus, - more primitive, ancient, and epicritical - newer, more complex, determined by the cerebral cortex. Ged's positions are not supported by modern data, although these terms are used in the clinic.

Specific differentiation of sensitivity is associated with the structural and physiological characteristics of the peripheral nerve fiber. Sensitive impulses arising in the receptor apparatus are carried out by fibers of different structure at different speeds depending on the severity of the myelin layer and the different frequencies of the electrical potential oscillations noted in this case. Structural and physiological differences also reflect the different functional significance of nerve fibers. Thus, group A fibers with a thick myelin sheath, carrying fast impulses, conduct deep and tactile sensitivity. Group B fibers with a thin myelin sheath, with slower impulses, conduct pain, temperature and tactile sensitivity and non-myelinated C fibers, slowly conducting impulses, diffuse non-localized pain.

All impulses arising in the peripheral apparatus of general sensitivity enter mainly through the posterior roots of the spinal cord into the central nervous system, where sensations arise. The emergence of any sensation is determined by the process of afferentation, the propagation of a specific impulse from the corresponding receptor along certain pathways. In response to this or that irritation, all departments of the corresponding analyzer are activated, and the usual sensation, according to the type of sensitivity, is always the result of a complex interaction of various mechanisms up to cortical ones, which, according to I.P. Pavlov, determine the analysis and synthesis of incoming impulses. Of great importance for a correct understanding of the central mechanisms of sensitivity is the consideration of its versatile interactions with the reticular formation, this kind of ascending, activating, so-called non-specific system of the brain. It is important that the reticular formation also exerts downward regulatory influences on the peripheral receptor apparatus and the process of afferentation in sensory pathways. Thus, sensitivity, which was previously considered only as a result of one-sided afferentation, passive conduction of receptor excitation in the central direction, acts as a complex system with double bonds, with an active effect on the flow of sensory impulses and constant regulation of the level of excitability of various localized links of sensitivity through facilitating and inhibitory influence. All these data create certain prerequisites for a correct assessment of the cortical-subcortical relationships in the mechanism of sensitivity.

Sensitivity is a property of a living organism, expressed in the perception of stimuli from the external environment and from its own tissues and organs. There are exteroceptive sensitivity (superficial), proprioceptive sensitivity (deep) and interoceptive, or vegetative-visceral, sensitivity (from internal organs, blood vessels, etc.). There are also complex types of sensitivity (stereognosis, etc.). The perception of irritations in humans exists only if the receptor is inextricably linked, i.e., the peripheral part of the sensitive analyzer (see), with its cortical section. The connection between these sections of the analyzer goes through a three-link chain of neurons.

Depending on which of the neurons is disturbed, one or another type of sensitivity disorder will be clinically observed, according to the nature of which the damage is diagnosed. For such a determination, it is necessary to know the anatomical course of sensitive pathways and the distribution of peripheral neurons.

Each segment of the spinal cord is connected through the posterior roots with a strictly corresponding skin segment. Irritations from the skin segments go along different peripheral nerves (for example, the cervicobrachial and lumbosacral plexus), therefore, with damage to the posterior roots, the pattern of loss of sensitivity differs from the loss of sensitivity observed with damage to the peripheral nerves (Fig.). This gives the right to speak of a sensitivity disorder of the peripheral and radicular type, that is, of the blockade of nerve impulses in the peripheral nerve trunk or in one or another posterior root of the spinal cord, which is noted with neuritis,. With the radicular type of loss of sensitivity, the segmental type of loss of sensitivity coincides geographically with damage to the posterior horn of any segment of the spinal cord. However, they are qualitatively different, since with the segmental type, sensitivity according to the dissociated type drops out, that is, only pain and temperature sensitivity, and deep sensitivity is preserved. This is due to the fact that the fibers of the posterior root are separated upon entering. The fibers that transmit impulses from the muscles and joints, without entering the posterior horn, go up the posterior columns in order to switch to the second neuron at the level of the medulla oblongata, which makes the transition to the opposite side and reaches the thalamus, from where the third neuron delivers the impulse to the posterior and anterior central gyri of the cerebral hemispheres. Thus, deep sensitivity is transmitted along the back pillars of the side of the same name. The posterior root fibers, through which pain and temperature sensitivity is transmitted, enter the gelatinous Roland substance of the posterior horn of the same segment of the spinal cord, where they switch to the second neuron, which, rising upward, passes in front of the central canal of the spinal cord to the opposite side and goes along the lateral column of the spinal cord. the brain, forming the spinothalamic pathway, reaches the thalamus opticus, and then, as part of the third neuron, the impulses reach the posterior central gyrus, i.e., the cortical part of the skin analyzer. Thus, the segmental type of sensitivity disorder, or otherwise the posterior type of sensitivity disorder, will be detected in cases where the patient has pain and temperature sensitivity on certain skin segments, and the deep one is not disturbed. So, for example, at (see) such sites of loss of sensitivity in the form of a jacket or a semi-jacket are well known, and at patients in these parts of a body often there are traces of the painless burns received earlier.

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High sensitivity in many cases is a disadvantage. Such a feature as the susceptibility of the head of the penis to irritants, in itself, does not pose any danger and does not threaten health. However, this property often affects the duration and quality of sex, which entails great psychological problems.

What are feelings associated with?

The ability for prolonged sexual intercourse for a man in most cases is a virtue. But in a certain way it depends on the general sensitivity of the organ. The faster and stronger the nerve endings react, and the more of them, alas, the faster the ejaculation occurs.

Strong sensitivity of the glans penis can be congenital or acquired. The congenital form is characterized by the persistence of symptoms for a long time, so the duration of sexual intercourse remains small both in adolescence and in a much more mature period, since the hormonal background does not matter here. But all the means leading to a dulling of sensitivity - ointments, condoms, are extremely effective.

If the changes occurred as a result of an illness, the signs may differ - they depend on the nature of the disease.

Prostatitis "provides" ejaculation with pain symptoms, up to the point that a man loses the ability to enjoy an orgasm. And with phimosis, ejaculation can occur before the onset of sexual intercourse and without any prior stimulation.

The congenital form of sensitivity is very difficult to correct. However, the use of condoms and special ointments solve this problem, but, however, they have to be used constantly. The acquired form is more or less associated with the primary disease. Sometimes surgery is needed to treat it.

Causes of increased sensitivity of the head

As already mentioned, there are 2 types of hypersensitivity - congenital and acquired. Congenital is due to an increased number of nerve endings. It is impossible to call such a condition a disease or pathology, this is really an individual feature that a man will have to come to terms with.

Acquired appears as a result of diseases:

• Phimosis - can be both congenital and acquired. In this case, the head of the penis is always closed or half-closed, because due to the short frenulum it is not released from the foreskin. As a result, the skin on the head is too sensitive. In the acquired form, the cause of incomplete exposure of the head is scarring of the tissue of the foreskin. The result is the same - hypersensitivity and inability to have prolonged sexual intercourse.
• Balanoposthitis is an inflammation caused by an infection, in this case, staphylococci. This condition exacerbates the sensitivity of nerve endings, and as a result, the reaction to stimuli is too violent.
• Prostatitis - indirectly affects the "work" of the penis, but in most cases makes ejaculation a painful process.
• Stress - nervous excitement provides a permanent erection, sometimes quite painful. At the same time, the sensitivity of the head increases dramatically, but under such circumstances, the disappearance of stress returns everything to normal.
• Hormonal imbalance - most often the cause in adolescence. During the period of hypersexuality, constant arousal turns into a short sexual intercourse. However, over time, this hypersensitivity disappears on its own, due to the alignment of hormonal levels.

High sensitivity and overexcitation

This feature should be distinguished from simple excessive excitement, which naturally occurs after prolonged abstinence or at a young age.

Signs of hypersensitivity of the glans penis are as follows:

• sexual intercourse is always short both at a young and at a more mature age;
• the duration does not depend on the number of repetitions, that is, both the second and third act per night are equally short. In ordinary overexcitation, the second act will always be longer;
• when using a condom and lubrication, the duration increases, since the head of the penis is protected from irritants and does not cause such a violent reaction. In this case, sperm is released only when the penis is still in the partner's vagina. Again, with ordinary overexcitation, the presence or absence of an excessive stimulus plays a much smaller role;
• when drinking alcohol, the duration of sex increases, which never happens when overexcited. This paradoxical reaction is due to the fact that alcohol dulls the sensitivity of nerve receptors;
• against the background of the use of prolongators, the time of sexual intercourse also increases;
• a special spray with lidocaine - a means to prolong sex. The mechanism of action is the same: lidocaine dulls the sensitivity.

It is important to distinguish between these 2 concepts to understand the essence of the problem. Ordinary overexcitation is a temporary phenomenon, it does not require any treatment. With hypersensitivity, certain measures have to be taken, since this problem cannot be solved by itself.

How to reduce?

A man's sexual abilities are affected by both purely objective external and internal factors - stress, cold, illness, as well as subjective ones - experiences, hypertrophied exactingness, and so on. Actually, the treatment, or rather the correction, of such a deficiency as the sensitivity of the head, is also possible by various methods, including self-hypnosis.

Medicines

This category includes both medications and medicines for external use, and even devices:

• A condom with dense latex walls is a simple and effective way to prolong an erection, since the material significantly reduces sensitivity. Many men complain about this feature of the condom, but in this case, the density of the film turns into a virtue.
• Additional nozzles - such a device can be found in a sex shop. The nozzle is fixed in place of the bridle and to some extent protects the head from too “close contact”.
• Anesthetic ointments - lidocaine spray, heparin ointment, SS cream, katagel, etc. Ointments reduce the sensitivity of nerve endings, which automatically solves the problem.
• Medicines - medicines are used that reduce the overall excitability of the nervous system - diprofen, papaverine. In addition, drugs designed to control ejaculation like Cialis or even Viagra have the same effect.
• Tonic - usually of plant origin. Drugs affect muscle tone, which helps to reduce sensitivity.
• Sedatives - with relatively mild nervous excitement, the usual infusion of motherwort or valerian can help. Potassium or sodium bromide works in the same way.
• Antidepressants - in particular, selective serotonin reuptake inhibitors - paxil, fluoxetine. Drugs relieve nervous tension and relieve obsessive-compulsive states.
• Tranquilizers - elenium, meprotan, are used for general excessive excitability and some mental disorders.

All drugs, in fact, are aimed at symptomatic treatment, that is, the elimination of sensitivity during intercourse. Physiological problems are healed more easily. But the solution of the psychological ones that provoked this syndrome requires both time and effort.

Folk methods

Excessive sensitivity of the head of the penis is not a problem today. Traditional medicine offers its own ways of healing.

Some of them are quite rational and applicable at home:

• Mint juice is a kind of "cooling" effect, reducing the sensitivity of nerve endings. Before sexual intercourse, it is recommended to lubricate the penis with juice.
• Cornflower tincture has a slight sedative effect and reduces excitability, which also helps to prolong sexual intercourse.
• Tincture of 5 g of hops and 15 g of motherwort - 800 ml of boiling water is poured and infused all night, reduces general excitability. Take the medicine three times a day, 150 ml for 1 month.
• The collection of equal parts of wild rose berries, viburnum, mountain ash and nettle leaves also has a tonic effect. All of the above components are poured with 1 cup of boiling water and left in a thermos for 30 minutes. Then the broth is filtered and drunk twice a day before meals, 1 tablespoon.
• Periwinkle tea also helps. 20 g of the dry mixture is poured into a water machine, boiled for at least 10 minutes, and then taken 10 drops twice a day for 5 days. This course is repeated again after 3 days.

Drinking alcohol also dulls the sensitivity. However, the use of this remedy is fraught with much more serious complications than premature ejaculation.

self control

There are certain techniques to reduce sensitivity and prolong the sexual act. Even with such a feature as a sensitive head.

However, mastering them requires a certain level of self-control:

• Start-stop - with some training, a man learns to predict the moment before the onset of orgasm. To prevent too rapid ejaculation, the penis at this moment is removed from the vagina and pinched at the base of the head. After a couple of seconds, overexcitation subsides and sexual intercourse can be continued. This technique can be repeated several times.

It is important to prevent ejaculation, not to stop it. If ejaculation has already begun, clamping can lead to reverse ejaculation and other disorders.

• In the same way, the cessation of frictions and a deep slow breath act. In this case, the loss of erection reaches 20-30%, which is enough to prolong sexual intercourse. The reception can be repeated, but for this, of course, you need to have a certain self-control.
• Kegel exercises - Kegel suggested that too fast ejaculation is associated with disorders in the innervation. He proposed to solve this problem with the help of special exercises involving the pelvic organs. This will not affect the sensitivity of the head in any way, but will allow the man to control his own erection to a greater extent and consciously prevent premature ejaculation.

The simplest exercise of this kind is the specific tension and relaxation of the pubococcygeus muscle, which occurs when trying to stop or delay urination. Such a cycle - contraction-relaxation, is performed 15 times 2-3 times a day. The load can be increased - contract the muscles up to 50 times. This practice helps to prevent too soon orgasm.

Another way to reduce sensitivity is to try to distract yourself during sexual intercourse: think about something unpleasant, or at least list in your mind the paragraphs of the next law adopted by the government.

Surgery

Surgical treatment is indicated only for phimosis, when the head is not completely exposed. In this case, the foreskin is simply cut off, and after a while the process returns to normal.

With excessive sensitivity of the head, surgery will not help. Some time ago, a neurosurgical intersection of the nerves responsible for the sensitivity of the head was proposed, but such an intervention is fraught with almost complete loss of sensitivity of the penis, and, therefore, a weakening of the erection. Today, the method is recognized as crippling and is not practiced.

The sensitive head of the penis is not a disease, but in most cases a feature of the body. It is not required to treat such a feature if the problem is not caused by some kind of ailment, and it is worth solving it with conservative methods.
On the video about the causes and methods of treatment of head sensitivity: