Definition

Analyzer - A functional unit responsible for perception and analysis of sensory information of one species (the term introduced I. P. Pavlov).

The analyzer is a combination of neurons involved in the perception of irritation, initiation and in the analysis of irritation.

The analyzer is often called sensory system. The analyzers are classified by the type of sensations, in the formation of which they are involved (see Fig. Below).

Fig. Analyzers

it visual, auditory, vestibular, flavor, olfactory, skin, muscular And other analyzers. Three departments are distinguished in the analyzer:

1. Peripheral department: receptor designed to convert irritation energy into nervous excitation process.
2. Conductive department: Chain from centripetal (afferent) and inserting neurons, according to which pulses are transmitted from receptors to the overlying departments of the central nervous system.
3. Central Division: A certain cortex zone of large hemispheres.

In addition to the ascending (afferent) paths, there are downward fibers (efferent), according to which the regulation of the lower levels of the analyzer from its higher, in particular the cortical, departments are carried out.

analyzer	peripheral department (senses and receptors)	conductive department	central Division
visual	retina receptors eyes	Speed \u200b\u200bnerve	summary center in the occipital fraction of the CBP
auditory	sensitive High Cordeeva Cells (Spiral) Snail Organ	auditory nerve	hearing center in the temporal share of the CBP
olfactory	ISELESTING NOS Epithelial Recipers	Obnuata nerve	obluent center in the temporal share of the CBP
flavor	taste kidney oral cavity (mainly the root of the language)	language nerve	taste Center in the temporal share of the CBP
tactile (tactile)	tanguage calves of the packer layer of the dermis (pain, temperature, tactile, etc. Receptors)	centripetal nerves; Spinal, oblong, intermediate brain	center of the skin sensitivity in the central urinets of the Dark Share of the CBP
skin-muscular	Sapororeceptors in muscles and bundles	centripetal nerves; spinal cord; oblong and intermediate brain	motor zone and adjacent areas of frontal and dark stakes.
vestibular	half-breached tube and anticipation of the inner ear	honor-Uddoven Nerve (VIII A pair of cranopy brain nerves)	cerebellum

KBP * - Bark of large hemispheres.

Sense organs

A person has a number of important specialized peripheral formations - sense organsproviding perception of external stimuli affecting the body.

The sense body consists of receptors and auxiliary which helps to catch, concentrate, focus, direct, etc. Signal.

The senses include organs of vision, hearing, smell, taste, touch. By themselves, they cannot provide a feeling. For the emergence of a subjective sensation, it is necessary that the excitation that occurred in the receptors entered into the appropriate bark department of large hemispheres.

Structural fields of large semi-bark

If we consider the integral organization of the crust of large hemispheres, then several fields having a different cell structure can be distinguished.

There are three main groups of fields in the Core:

• primary
• secondary
• tertiary.

Primary fields, or nuclear analyzers, directly related to the senses and movement bodies.

For example, a field of pain, temperature, skin-muscular sensitivity in the back of the central ispiled, the visual field in the occipital fraction, the auditory field in the temporal share and the motor field in the front of the central ispud.

Primary fields they used to ripen in ontogenesis.

The function of primary fields: analysis of individual irritations entering the bark from the corresponding receptors.

In the destruction of the primary fields, the so-called cork blindness, cortic deafness, etc. occurs, etc.

Secondary fields Located next to the primary and connected through them with the senses.

Secondary field function: generalization and further processing of incoming information. Separate sensations are synthesized in them into complexes that cause perception processes.

With the defeat of secondary fields, a person sees and hears, but not able to realizeunderstand the value seen and heard.

Primary and secondary fields are also in person, and in animals.

Tertiary fields, or the zones of overlapping analyzers, they are in the rear half of the bark - on the border of the dark, temporal and occipital fractions and in the front parts of the frontal fractions. They take half of the entire area of \u200b\u200bthe cortex of large hemispheres and have numerous connections with all its parts.In the tertiary fields, most of the nerve fibers connecting the left and right hemisphere are ends.

Tertiary field function: Organization of coordinated work of both hemispheres, analysis of all perceived signals, their comparison with previously obtained information, coordination of relevant behavior,programming motor activity.

These fields are only in human people ripen later than other cortical fields.

The development of tertiary fields in humans is associated with speech function. Thinking (inner speech) is possible only with the joint activities of the analyzers, the combination of information from which occurs in tertiary fields.

With congenital underdevelopment of tertiary fields, a person is not able to master the speech and even the simplest engine skills.

Fig. Structural fields of large semi-bark

Taking into account the location of the structural fields of the crust of large hemispheres, the functional parts can be distinguished: sensory, motor and associative zones.

All sensory and motor zones occupy less than 20% of the surface of the crust. The remaining Cora is an associative area.

Associative zones

Associative zones - this is functional zones cortex brain. They bind newly incoming sensory information from the memory previously and stored in blocks, and also compare the information obtained from different receptors (see Fig. Below).

Each associative bark area is associated with several structural fields. The composition of associative zones includes a part of a dark, frontal and temporal fraction. The boundaries of associative zones are fuzzy, its neurons are involved in the integration of various information. Here is the highest analysis and synthesis of irritation. As a result, complex elements of consciousness are formed.

Fig. Furrows and shares of the bark of large hemispheres

Fig. Associative bark zones of large hemispheres:

1. Ass scitizable enginea zone(frontal share)

2. Primary motor zone

3. Primary somatosensory zone

4. Dark share of large hemispheres

5. Associative somatosensory (skin-muscular) zone (Dark Share)

6. Associative visual zone(occipital share)

7. The occipital proportion of large hemispheres

8. Primary visual zone

9. Associative hearing area(temporal shares)

10. Primary hearing area

11. Tempory share of large hemispheres

12. The olfactory bark (the inner surface of the temporal share)

13. Flag of bark

14. Ensure associative zone

15. The frontal share of large hemispheres.

Sensory signals in the associative zone are deciphered, comprehended and used to determine the most suitable responses that are transmitted to the associated motor (motor) zone.

Thus, associative zones participate in memorization processes, learning and thinking, and the results of their activities are intelligence (body's ability to use the knowledge gained).

Separate large associative areas are located in the cortex next to the corresponding sensory zones. For example, the visual associative zone is located in the occipital zone directly ahead of the sensory visual zone and provides full processing of visual information.

Some associative zones perform only part of information processing and are associated with other associative centers that further processing. For example, the audio associative zone analyzes the sounds, separating them into categories, and then transmits signals to more specialized zones, such as a speech associative zone, where the meaning of the heard words is perceived.

These zones belong to associative Kore And participate in the organization of complex forms of behavior.

In the crust of large hemispheres allocate areas with less defined functions. So, a significant part of the frontal fraction, especially on the right side, can be removed without noticeable violations. However, if we produce two-way removal of frontal areas, severe mental disorders arise.

taste analyzer

Taste analyzer Responsible for the perception and analysis of taste sensations.

Peripheral department: Receptors - flavoring bulbs in the mucous membrane of the language, soft sky, almonds and other organs of the oral cavity.

Fig. 1. Taste nipples and flavoring bulbs

Taste nipples are carried on the side surface of the flavoring bulbs (Fig. 1, 2), which include 30 - 80 sensitive cells. Taste cells are littered at their end microwaves - flavoring hairs. They go to the surface of the tongue through the taste. Taste cells are continuously divided and continuously dying. Especially quickly, the cells are replaced by cells located in the front of the language, where they lie more superficially.

Fig. 2. Flavoring bulbs: 1 - nervous flavoring fibers; 2 - flavor kidney (cup); 3 - taste cells; 4 - support (reference) cells; 5 - taste time

Fig. 3. Taste zones of the language: Sweet - tip of the language; bitter - base language; sour - side surface of the tongue; Salted - tip of the tongue.

Taste sensations cause only substances dissolved in water.

Conductive department: Fiber Facial and Language nerve (Fig. 4).

Central Division: The inner side of the temporal fraction of the bark of large hemispheres.

olfactory analyzer

Olfactory analyzer Responsible for the perception and analysis of the smell.

• food behavior;
• approbation of food on edible;
• setting the digestive apparatus for food processing (according to the conditional reflex mechanism);
• defensive behavior (including manifestation of aggression).

Peripheral department: Recipers of the mucous membrane of the top of the nasal cavity. The olfactory receptors in the nasal mucosa energles with olfactory cilia. Gaseous substances dissolve in mucus surrounding cilia, then a nervous impulse arises as a result of a chemical reaction (Fig. 5).

Conductive department: olfactory nerve.

Central Division: The olfactory bulb (the structure of the front brain, in which the processing of information is carried out) and an olfactory center located on the lower surface of the temporal and frontal fraction of the crust of large hemispheres (Fig. 6).

The smell is determined in the cortex and the body's response adequate is formed.

The perception of taste and smell complement each other, giving a holistic idea of \u200b\u200bthe form and quality of food. Both analyzers are associated with the center of salivation of the oblong brain and participate in the nutritional reactions of the body.

The tactile and muscle analyzer is combined into somatosensory system- Survicious sensitivity system.

Building a somatosensory analyzer

Peripheral department: proproporeceptors muscles and tendons; Skin receptors ( mechanoreceptors, thermoreceptors, etc.).

Conductive department: afferent (sensitive) neurons; ascending spinal cord paths; An oblong brain, the core of the intermediate brain.

Central Division: Sensory zone in a parietal bark of large hemispheres.

Skin receptors

The skin is the largest sensitive organ in the human body. Many receptors are concentrated on its surface (about 2 m2).

Most scientists are inclined to prevent four main types of skin sensitivity: tactile, thermal, cold and pain.

Receptors are unevenly distributed at different depths. Most receptors in the skin of the fingers, palms, soles, lips and genital organs.

Mechanoreceptors leather

• thin end of nerve fibers, powered blood vessels, hair bags, etc.
• merkel cells - nerve endings of the basal layer of the epidermis (a lot on the pillows of the fingers);
• tanguitive Maissener Taurus - complex papillary layer receptors of the dermis (a lot on the fingers, palms, soles, lips, tongue, genital organs and the nipples of the mammary glands);
• plate Tales - pressure and vibration receptors; located in deep layers of the skin, in tendons, bundles and mesenter;
• bulb (flabs Krause) - Nervous receptors inthe connected bed of mucous membranes, under the epidermis and among muscle tongue fibers.

Mechanism of operation of mechanoreceptors

Mechanical stimulus - Deformation of the receptor membrane - a decrease in the electrical resistance of the membrane - an increase in the permeability of the membrane for Na + - depolarization of the receptor membrane - the propagation of the nerve impulse

Adaptation of skin mechanoreceptors

• quickly adapting receptors: Skin mechanoreceptors in hair bulbs, lamellar tales (do not feel the pressure of clothing, contact lenses, etc.);
• slowly adaptable receptors: Tanguitive Maissener Taurus.

The feeling of touching and pressure on the skin is quite accurately localized, i.e. it refers to a person to a certain section of the skin surface. This localization is produced and fixed in ontogenesis with the participation of vision and proproporesis.

The ability of a person separately perceive the touch towards two adjacent points of the skin, is also very different in different areas. On the mucous membrane of the language, the threshold of spatial difference is 0.5 mm, and on the skin of the back - more than 60 mm.

Temperature reception

The human body temperature fluctuates in a relatively narrow limits, so information on the ambient temperature required for the activity of thermoregulation mechanisms is particularly important.

The thermistors are located in the skin, the cornea of \u200b\u200bthe eye, in the mucous membranes, as well as in the CNS (in the hypothalamus).

Types of thermistors

• cold thermistors: numerous; Lying close to the surface.
• heat thermoreceptors: their significantly less; La in a deeper skin layer.

• specific thermistors: perceive only temperature;
• nonspecific thermistors: Perceive temperature and mechanical stimuli.

The thermoreceptors react to a change in temperature with an increase in the frequency of generated pulses, which is stable all the time of the stimulus. The temperature change by 0.2 ° C causes long changes to their impulse.

In some conditions, cold receptors can be excited by heat, and thermal cold. This explains the occurrence of the acute sensation of the cold with a rapid immersion in a hot bath or the burning effect of icy water.

The initial temperature sensations depend on the difference in the temperature of the skin and the temperature of the active stimulus, its area and the application location. So, if the hand was kept in the water temperature 27 ° C, then at the first moment when transferring a hand to the water heated to 25 ° C, it seems cold, but after a few seconds the true estimate of the absolute water temperature becomes possible.

Painful reception

Pain sensitivity is of paramount importance for the survival of the body, being a signal of danger in strong influences of various factors.

Pulses of pain receptors often indicate pathological processes in the body.

At the moment, the specificities of pain receptors are not found.

Two hypotheses about the organization of pain perception are formulated:

1. Exist Specific pain receptors - free nervous endings with a high reaction threshold;
2. Specific pain receptors does not exist; Pain occurs with ultra-shaped irritation of any receptors.

The mechanism of excitation of receptors with painful influences is not yet clarified.

The most common cause of the occurrence of pain can be considered a change in the concentration of H + in the toxic effect on the respiratory enzymes or during damage to cell membranes.

One of possible causes Long-term burning pain may be released by damage to histamine cells, proteolytic enzymes, etc. substances causing a chain of biochemical reactions leading to the excitation of nerve endings.

Pain sensitivity is practically not represented at the cortical level, therefore the highest center of pain sensitivity is the Talamus, where 60% of neurons in the respective nuclei is reacting to painful irritation.

Adaptation of pain receptors

The adaptation of pain receptors depends on numerous factors and its mechanisms have been little studied.

For example, the zanosis, being motionless, does not cause special pain. Older people in some cases are "getting used to not notice" headaches or joint pain.

However, in very many cases, pain receptors do not detect substantial adaptation, which makes suffering the patient especially long and painful and requires the use of analgesics.

Pain irritations cause a number of reflex somatic and vegetative reactions. With moderate severity, these reactions have an adaptive value, but can lead to severe pathological effects, such as shock. Among these reactions, an increase in muscle tone, heart rate and respiration frequencies, an increase in pressure decrease, narrowing of pupils, an increase in blood glucose content and a number of other effects are noted.

Localization of pain sensitivity

In case of painful influences, a person localizes them fairly accurately, but if diseases of the internal organs can rose reflected pain. For example, with renal colic, patients complain about "entering" sharp pains in the legs and rectum. There may be reverse effects.

sproporec fee

Types of proproporeceptors:

• nervous muscular vertene: give information about the speed and power of muscle stretching and cutting;
• golgi tendon receptors: give information about the power of muscle contraction.

Spring Reference Functions:

• perception of mechanical irritation;
• perception of spatial location of body parts.

Nervous muscular spine

Nervous muscular spine - A complex receptor, which includes modified muscle cells, afferent and efferent nervous processes and controls both the speed and the degree of reduction and stretching of skeletal muscles.

Nervous muscular spindle is located in the thickness of the muscles. Each spindle is covered with a capsule. Inside the capsule is a bundle of special muscle fibers. The spindles are located in parallel with the fibers of skeletal muscles, so when tensile the muscles, the load on the spindle increases, and when the reduction is reduced.

Fig. Nervous muscular spine

Golgi tendon receptors

Are in the zone of muscle fibers with tendon.

Tender receptors weakly react to muscle stretching, but are excited when it is reduced. The intensity of their impulsation is approximately proportional to the strength of the muscle contraction.

Fig. Golgi tendon receptor

Articular receptors

They are learned less than muscle. It is known that the articular receptors react to the position of the joint and on the changes in the joint corner, thus participating in the feedback system from the propeller and in the management of them.

The visual analyzer includes:

• peripheral department: retina receptors of the eye;
• conductive department: optic nerve;
• central Department: The occipital proportion of the bark of large hemispheres.

The function of the visual analyzer: perception, conducting and decoding of visual signals.

Eyes building

The eye consists of eyeball and auxiliary apparatus.

Auxiliary apparatus Eyes

• eyebrows - protection against sweat;
• eyelashes - protection against dust;
• century - mechanical protection and maintaining humidity;
• tooth glands- Located at the top of the outer edge of the orbit. It highlights a tear liquid, moisturizing, washing and disinfecting eyes.Excess tear fluid is removed into the nasal cavity through tears Canallocated in the inner corner of the socket .

EYEBALL

The eyeball has an approximately spherical shape with a diameter of about 2.5 cm.

It is located on a fat pillowin the front of the orders.

The eye has three shells:

1. bell shell (scler) with a transparent cornea - outer very dense fibrous eye sheath;
2. vascular shell with an outer rainbow shell and ciliary body - permeated with blood vessels (eagle nutrition) and contains a pigment that prevents the scattering of light through the scler;
3. retina (retina) - the inner sheath of the eyeball -receptor part of the visual analyzer; Function: Direct perception of light and transfer information to the central nervous system.

Konjuktiva- mucous membrane connecting the eyeball with skin cover.

Soft shell (sclera) - outer durable eye sheath; The inner part is impenetrable for network rays. Function: Protection of the eye from external influences and light insulation;

Cornea - front transparent part of the sclera; It is the first lens on the path of light rays. Function: Mechanical eye protection and transmitting light rays.

Crystalik - Two-point lens, located behind the cornea. LCD function: focusing light rays. Crystalik does not have vessels and nerves. It does not develop inflammatory processes. It has many proteins that can sometimes lose their transparency, which leads to a disease called cataract.

Vascular shell - The middle sheath of the eye rich in vessels and pigment.

Iris - front pigmented part of the vascular shell; Contains pigments melanin and lipofuscin, Determining eye color.

Pupil - Round hole in the rainbow shell. Function: Regulation of the light flux entering the eye. The diameter of the pupil is involuntarily changing using smooth muscles Rainbow shellwhen changing light.

Front and rear cameras - Space front and rear of the rainbow shell filled with transparent liquid ( water moisture).

Ciliary (ciliary) body - part of the middle (vascular) eye shell; Function: crust fixation, ensuring the process of accommodation (curvature change) lens; Production of water and thermoregulation chamber moisture.

Vitreous body - The cavity of the eye between the crust and the eye filled with a transparent viscous gel that supports the shape of the eye.

Retina (Retina) - Receptor apparatus of the eye.

Structure of retina

The retina is formed by the ramifications of the expirational nerve, which, approaching the eyeball, passes through the butter, and the nerve shell merges with the eye sheath. Inside the eye, the nerve fiber is distributed in the form of a thin mesh shell, which sweeps the rear 2/3 of the inner surface of the eyeball.

The retina consists of reference cells forming a mesh structure, from where its name occurred. Light rays perceives only its back. The mesh shell in its development and the function is part of the nervous system. Nevertheless, the other parts of the eyeball play auxiliary role to perceive the retina of visual irritation.

Retina - This is a part of the brain, extended outside, closer to the surface of the body, and maintains communication with it using a pair of optic nerves.

Nervous cells form in the retina chain, consisting of three neurons (see Fig. Below):

• the first neurons have dendrites in the form of sticks and colodes; These neurons are finite cells of the optic nerve, they perceive visual irritation and are light receptors.
• second - bipolar neurons;
• third - multipolar neurons ( ganglion cells); Axons are departed from them, which stretch through the bottom of the eye and form a visual nerve.

Free-sensitive retinal elements:

• sticks - perceive brightness;
• columns - perceive the color.

Columns are slowly excited and only bright light. They are able to perceive the color. In the retina there are three types of colums. The first is perceived red, the second is green, the third is blue. Depending on the degree of excitement of colums and combinations of irritation, the eye perceives various colors and shades.

Sticks and columns in the mesh shell are mixed with each other, but in some places they are located very thickly, in others they are rarely or missing at all. Each nerve fiber accounts for about 8 wizards and about 130 sticks.

In area yellow spots There are no sticks on the retina - only kolkochki, here the eye has the greatest urgency of view and the best perception of color. Therefore, the eyeball is in a continuous movement, so that the considered part of the object occurred on the yellow spot. As it removes from the yellow spot, the density of the sticks increases, but then decreases.

With low light in the process of vision, only wands (twilight vision) are involved, and the eye does not distinguish colors, the vision turns out to be ahromatic (colorless).

Nervous fibers deploy from sticks and colodes, which, connecting, form a visual nerve. The place of exit from the retina of the optic nerve is called Disk of optic nerve. In the area of \u200b\u200bthe disk of the optic nerve of the photosensitive elements. Therefore, this place does not give a visual sensation and is called blind spot.

Muscles Eyes.

• overall muscle - three pairs of cross-striped skeletal muscles that are attached to the conjunction; carry out the movement of the eyeball;
• muscles pupil - smooth iris muscles (circular and radial), changing the diameter of the pupil;
  The circular muscle (compressor) of the pupil is innervated by parasympathetic fibers from the glasses, and the radial muscle (expander) of the pupil - the fibers of the sympathetic nerve. Rainbow shell, thus adjusts the amount of light entering the eye; With a strong, bright light, the pupil is narrowed and limits the receipt of rays, and with weak - expands, giving the opportunity to penetrate more rays. The diameter of the pupil affects the hormone of adrenaline. When a person is in an excited state (under fright, anger, etc.), the amount of adrenaline in the blood increases, and it causes the expansion of the pupil.
  Muscle movements of both pupils are controlled from one center and occur synchronously. Therefore, both pupils are always equally expanding or narrowed. Even if you turn the bright light on the eye alone, the pupil of another eye is also narrowing.
• crustal muscles (ciliary muscles) - smooth muscles, changing the curvature of lens ( accommodation - focus image on the retina).

Conductive department

The optic nerve is a conductor of light irritation from the eye to the auditorium and contains sensitive fibers.

Out of the rear pole of the eyeball, the optic nerve comes out of the eye and, entering the cavity of the skull, through the auditorium, along with the same nerve of the other side, forms a cross ( hiazmu) under hypolalamus. After crossing, visual nerves continue in visual tracts. The optic nerve is associated with the nuclei of the intermediate brain, and through them - with the crust of large hemispheres.

Each visual nerve contains a totality of all the processes of the retinal nerve cells of one eye. In the area of \u200b\u200bthe Hiazma, there is incomplete crosspoints, and about 50% of the fibers of the opposite side and as much fibers of its part are in each visual tract.

Central Division

The central department of the visual analyzer is located in the occipital fraction of the bark of large hemispheres.

The pulses from light irritation in a visual nerve pass to the brain core of the occipital share, where the auditorium is located.

In the fibers of each nerve are associated with two hemispheres of the brain, and the image obtained on the left half of the retina of each eye is analyzed in the visual crust of the left hemisphere, and on the right half of the retina in the crust of the right hemisphere.

vision vision

With age and under the influence of other reasons, the ability to control the curvature surface of the lens is weakening.

Myopia (myopia) - focusing image before the retina; It develops due to an increase in lens curvature, which may occur with improper metabolism or impaired hygiene of view. ANDcreate glasses with concave lenses.

Farcastic - Focus image behind the retina; It arises due to a decrease in crust convexity. ANDcall glasseswith convex lenses.

There are two ways to conduct sounds:

• air conduction: Through the outer hearing pass, the eardrum and a chain of auditory bones;
• fabric conductivityb: Through the tight fabrics.

The function of the auditory analyzer: perception and analysis of sound irritation.

Peripheral department: Hearing receptors in the cavity of the inner ear.

Conductive department: Hearing nerve.

The central department: the auditory area in the temporal share of the bark of large hemispheres.

Fig. Temporal bone rice The location of the hearing body in the cavity of the temporal bone

Ear structure

The human hearing body is located in the skull cavity in the thickness of the temporal bone.

It is divided into three departments: outdoor, secondary and inner ear. These departments are closely related anatomically and functionally.

Outdoor Ear It consists of an outdoor auditory passage and ear shell.

Middle ear - drum cavity; It is separated by a drumpoint from the outdoor ear.

Interior Ear, or Maze- the ear department, where irritation of the recipers of the auditory (sniteloboy) nerve occurs; It is placed inside the pyramid of the temporal bone. The inner ear forms an organ of hearing and equilibrium.

Outdoor and secondary ear have secondary importance: they conduct sound oscillations to the inner ear, and thus is a sound-conducting machine.

Fig. Ear departments

Outdoor Ear

Outdoor ear includes ear shell and external hearing aislewhich are designed to capture and conduct sound oscillations.

Auricle Formed by three tissues:

• the thin plate of the hyaline cartilage covered on both sides by a superchloride having a complex convex-concave shape that determines the relief of the auricle;
• skin is very thin, tightly adjacent to the sketch and almost no fatty fiber;
• subcutaneous fatty tissue, located in a significant amount in the lower part of the ear shell - urban ear.

The ear shell is attached to the temporal bones with ligaments and has rudimentary muscles that are well expressed in animals.

The ear sink is arranged so as to maximize the sound of sound oscillations and direct them into the outer auditory.

The shape, the amount, formulation of the ear shells and the size of the auric loss are individual from each person.

Darwin Budrock - Rudimentary triangular protrusion, which is observed in 10% of people in the upper back area of \u200b\u200bthe shell curl; It corresponds to the top of the ear of animals.

Fig. Darwin Budrock

Outdoor auditory pass It is an S-shaped tube of about 3 cm and a diameter of 0.7 cm, which opens with a hearing aid and separated from the middle ear cavity drumpowder.

The cartilage part, which is a continuation of the cartilage of the auricle, is 1/3 of its length, the remaining 2/3 are formed by the bone canal of the temporal bone. At the junction of the cartilage department, the bone canal is narrowed and bend. This place is a bunch of elastic connective tissue. Such a structure makes it possible to stretch the cartilaginous department of the passage in length and in width.

In the cartilage part of the auditory pass, the skin is covered with short hairs that protect small particles from entering the ear. Swimming glands open in the hair follicles. Characteristic of the skin of this department is the presence in the deeper layers of the sulfuric glands.

Sulfurges are derivatives of sweat glands. The iron glands fall into either hair follicles, or freely into the skin. Sulfur glands highlight a light yellow secret, which together with the separated sebaceous glands and with a tightened epithelium forms ear sulfur.

Earwax - The light yellow secret of the sulfuric gland of the external auditory pass.

The sulfur consists of proteins, fats, fatty acids and mineral salts. Part of the proteins are immunoglobulins defining protective function. In addition, the composition of sulfur includes dead cells, skin fat, dust and other inclusions.

Function of ear sulfur:

• moisturizing the skin of the outer auditory passage;
• purification of an auditory pass from foreign particles (dust, sera, insects);
• protection against bacteria, fungi and viruses;
• fat lubricant in the outer part of the auditory pass prevents water from entering it.

Ear sulfur with pollution is naturally excreted from the auditory pass outside with chewing movements and speech. In addition, the skin of the auditory passage is constantly updated and grows out from the auditory passage, pulling out sulfur with him.

Interior bone Outdoor auditory passes is a channel of temporal bone ending the eardrum. In the middle of the bone department there is a narrowing of the auditory passage - the experiencies, followed by a wider section.

The skin of the bone department is thin, does not contain hair bulbs and glands and moves to the eardrum, forming its outer layer.

Eardrum representsthin oval (11 x 9 mm) translucent plate, impenetrable for water and air. Membraneit consists of elastic and collagen fibers, which in the upper part of it are replaced by fibers of loose connective tissue.From the side of the hearing pass, the membrane is covered with a flat epithelium, and from the side of the drum cavity - the epithelium of the mucous membrane.

In the central part, the eardrum is concave, the handle hammer is attached to it from the drum cavity - the first hearing bone of the middle ear.

The eardrum is laid and developing together with the external ear bodies.

MIDDLE EAR

The middle ear includes a mucous membrane lined and filled with air baban cavity (volume about 1 fromm.3 cM3.), three auditory bones and hearing (Evstachiev) Pipe.

Fig. Middle ear

Drum cavity Located in the thickness of the temporal bone, between the eardrum and the bone labyrinth. Hearing bones, muscles, bundles, vessels and nerves are placed in the drum cavity. The walls of the cavity and all the organs in it are covered with mucous membrane.

In the partition separating the drum cavity from the inner ear, there are two windows:

• oval window: Located in the upper part of the partition, leads on the eve of the inner ear; covered by the base is the perennial;
• round window: Located in low part of the partition, leads to the beginning of a snail; Closed by a secondary eardrum.

In the drum cavity there are three auditory bones: hammer, anvil and stirrup (\u003d dying). Hearing bones have small sizes. Connecting between themselves, they form a chain that stretches from the eardrum to oval hole. All bones are connected to each other with joints and covered with mucous membrane.

Hammer The handle is combed with a drumpoint, and the head with a joint is connected to anvilwhich in turn is movably connected to strive. The base of the stirrup closes the Oval Threadmaster Window.

The muscles of the drum cavity (pulling the eardrum and dying) hold the auditory bones in the voltage state and protect the inner ear from excessive sound irritations.

Hearing (Eustachiev) Pipe connects the drum cavity of the middle ear with the nasopharynk. it a muscular tube that is revealed when swallowing and yawn.

The mucous membrane, lining the hearing pipe, is a continuation of the nasopharynx mucosa, consists of a flicker epithelium with the movement of cilia from the drum cavity in the nasopharynk.

Functions of the Eustachius Pipe:

• balancing pressure between the drum cavity and the external environment to maintain the normal operation of the sound hardware;
• protection against infections penetration;
• removal from the drum cavity by accidentally penetrated particles.

Interior Ear

The inner ear consists of a bone and interputed labyrinth inserted into it.

Bone labyrinth Consists of three departments: spearness, snails and three semicircular channels.

Spell - the cavity of small sizes and incorrect form, on the outer wall of which are two windows (round and oval), leading to the drum cavity. The front part of the opposition communicates with the snail through the Staircase of the Threshore. The rear part contains two pressure for bags of the vestibular apparatus.

Snail - bone spiral channel in 2.5 turns. Snail axis lies horizontally and called the bone rod snail. A bone spiral plate is wrapped around the rod, which partially blows up a spiral snail channel and divides it on the staircase in anticipation and Drum stairs. Between themselves they communicate only through the hole at the top of the snail.

Fig. Snail structure: 1 - basal membrane; 2 - Cortis organ; 3 - Reisner Membrane; 4 - Staircase Extension; 5 - spiral gangli; 6 - drum staircase; 7 - predver curl nerve; 8 - spindle.

Semicircular canals - bone formations located in three mutually perpendicular planes. Each channel has an extended leg (ampule).

Fig. Snail and semicircular channels

Meat Labyrinth Filled endolimfoy and consists of three departments:

• webbed snail, orsnelled duct Continuation of the spiral plate between the staircase of the forever and the drum staircase. Hearing receptors are in the snail duct -spiral, or cortiyev, organ;
• three semicircular channels and two bagslocated on the eve of which play the role of the vestibular apparatus.

Between the bone and connecting labyrinth is perilimfa- Confired spinal fluid.

Cortiev Organ

On a plate of snelled duct, which is a continuation of the bone spiral plate, is located cortiev (Spiral) Organ.

The spiral body is responsible for the perception of sound irritation. It serves as a microphone transforming mechanical oscillations into electrical.

Cortiev organ consists of reference andsensitive Hair Cells.

Fig. Cortiev Organ

Hair cells have hairs that rise above the surface and reach the coating membrane (textory membranes). The latter departs from the edge of the spiral bone plate and hangs over the cortis organ.

In case of sound irritation of the inner ear, fluctuations of the main membrane appear on which the hairs cells are located. Such oscillations cause the ignition and compression of hairs about the cover membrane, and the nervous impulse in the sensitive neurons of the spiral ganglium is delivered.

Fig. Hair cells

Conductive department

Nervous impulse from the hair cells applies to spiral ganglium.

Then by auditory ( sentence and sniffy) nervethe impulse enters the oblongable brain.

In the Varoliye Bridge, part of the nerve fibers through the crossroads (Hiazma) passes to the opposite direction and go in the four brain quirme.

The nerve impulses through the nucleus of the intermediate brain are transmitted to the hearing area of \u200b\u200bthe temporal fraction of the bark of large hemispheres.

Primary hearing centers serve to perceive the auditory sensations, secondary - for their processing (understanding of speech and sounds, the perception of music).

Fig. Hearing analyzer

The facial nerve passes along with an auditory nerve in the inner ear and under the mucous membrane of the middle ear follows to the base of the skull. It can be easily damaged when inflammation of the middle ear or skull injuries, so violations of hearing organs and equilibrium are often accompanied by paralysis of the Mimic muscles.

Physiology of hearing

The hearing function of the ear is provided by two mechanisms:

• soundwork: conducting sounds through the outdoor and secondary ear to the inner ear;
• sound perception: Perception of sounds of the Cortiene Cortiev receptors.

Soundwork

The outdoor and secondary ear and perilimph of the inner ear belong to the sound-conducting device, and the inner ear, that is, the spiral body and the leading nervous paths - to the surning device. Through its own sink, due to its form, concentrates sound energy and directs it towards the outer auditory passage, which conducts sound oscillations to the eardrum.

Having reached the eardrum, sound waves cause its oscillation. These oscillations of the eardrum are transmitted to the hammer, through the joint to the anvil, through the joint - to the stirrup, which closes the Thread Start window (oval window). Depending on the phase of sound oscillations, the base of the stirrup is cleaned into the labyrinth, it is pulled out of it. These movements of the stirrups cause perilimphs oscillation (see Fig.), Which are transmitted to the main snail membrane and on the Cortian organ located on it.

As a result of oscillations of the main membrane, the hair cells of the spiral organ hurt over the coating (teterial) membrane over them. At the same time, stretching or compressing hairs occurs, which is the main mechanism for the conversion of mechanical oscillations to the physiological process of nervous excitation.

Nervous impulse is transmitted by the endings of the auditory nerve to the cores of the continued brain. Hence the impulses pass on the relevant leading paths to the auditory centers in the temporal parts of the cerebral cortex. Here, nervous excitement turns into a feeling of sound.

Fig. Sound signal path: Own sink - an outer hearing aisle - a drumpock - a hammer - anvil - a stemchko-oval window - the inversion of the inner ear - the staircase of the exterior - the basal membrane - the body cells of the Cortiev organ. Path of nervous impulse: Cortiev's hair cells - spiral gangli - the hearing nerve - the oblong brain - the core of the intermediate brain - the temporal share of the bark of large hemispheres.

Sound perception

A person perceives the sounds of the external environment with a frequency of oscillations from 16 to 20,000 Hz (1 Hz \u003d 1 oscillation for 1 s).

High-frequency sounds are perceived low part Curl, and low-frequency sounds - its top.

Fig. Schematic representation of the main snail membrane (indicated frequencies distinguishable by different sections of the membrane)

Otteni. - fromamendment to determine the location of the sound source in cases where we do not see it, is called. It is associated with the symmetric function of both ears and is regulated by the activity of the central nervous system. Such ability arises because the sound that goes on the side falls into different ears not at the same time: in the ear opposite side - with a delay of 0.0006 s, with another intensity and in another phase. These differences of sound perception with different ears make it possible to determine the direction of the sound source.

Analyzer - Functional system consisting of:

- receptor,

- Sensitive Way

- the corresponding zone of the cortex, where this type of sensitivity is projected.

Analysis and synthesis of obtained information are carried out in a strictly defined area - large hemisphey cortex.

According to the features of the cellular composition and structure, the bark of large hemispheres are divided into a number of areas called correspondent fields. The functions of individual sections of the cortex of unequal. Each receptor apparatus on the periphery corresponds to the area in the crust - the cortical core of the analyzer.

The most important corn zones Next:

Motor zone Located in the renamentral and risentent areas of the cortex (the front central winding ahead of the central furrow of the frontal share).

Sensitive zone (The area of \u200b\u200bthe skin-muscular sensitivity is located behind the central furrow, in the rear central urinet of the parietal lobe). The largest square occupies the cortical representation of the brush receptors and the thumb, the voice apparatus and the face, the smallest - representation of the body, hips and tibia.

Visual zone Focused in the occipital bark. It receives impulses from the retina of the eye, it carries out the distinction of visual irritation.

Hearing zone Located in the upper temporal winding of the temporal share.

Olfactory and taste zone - In the forefront (on the inner surface) of the temporal share of each hemisphere.

In our consciousness, the activities of the analyzers reflect the external material world. This makes it possible to adapt to environmental conditions by changing behavior.

The activity of the cerebral cerebral human and higher animals is defined by I.P. Pavlov as higher nervous activitywhich is a conditional reflex function of the cerebral cortex.

Analyzers - A combination of nervous formations that ensure awareness and assessment acting on the body, irritants. The analyzer consists of perceiving irritation of receptors, conductive part and the central part - a certain area of \u200b\u200bthe cortex of the brain, where the sensations are formed.

Spectator analyzer provides visual information from the environment and consists of three parts:

peripheral - eye,

conductive - optic nerve

central - subcortical and visual zone of the cerebral cortex.

Eye it consists of an eyeball and auxiliary apparatus, to which there are eyelids, eyelashes, laundry glands and muscles of the eyeball.

Eyeball located in the eye and has a spherical shape and 3shell:

fibrous, The rear department of which is formed opaque white shell ( scleria),

vascular

mesh

Part of the vascular shell, supplied with pigments, is called rainbow sheath.

In the center of the rainbow shell is pupilwhich can change the diameter of its hole by reducing the eye muscles.

Back back Perceives light irritation. Front part of it - blind and does not contain photosensitive elements. Photosensitive elements The retina are:

sticks (Provide vision at dusk and darkness)

columns (Color view receptors working at high illumination).

Columns are located closer to the retinal center (yellow spot), and the sticks are concentrated on its periphery. The venue of the visual nerve is called blind spot.

The cavity of the eyeball is filled vitreous body.

Crystalik It has the shape of a bicon-like lens. He is able to change its curvature when cutting the ciliac muscle. When viewed by close objects, the crystal is compressed, when viewed by remote - expands. Such an ability of the lens is called accommodation. Between the cornea and iris are front camera eye, between the iris and lens - rear camera. Both chambers are filled with transparent liquid. Rays of light, reflected from the items, pass through the cornea, wet chambers, a crystal, a vitreous body and, due to refraction in the lens, fall on yellow spot The retina is the place of the best vision. At the same time arises valid, reverse, reduced object image.

From the retina for visual nerve, the impulses go to the central part of the analyzer - cerebrallocated in the occipital share. In the cortex information obtained from retina receptors is processed and the person perceives the natural reflection of the object.

Normal spectacular perception Conditioned:

- sufficient light stream;

- focusing the image on the retina (focusing before the retina means myopia, and behind the retina - hyperopia);

- implementation of accommodation reflex.

The most important indicator of vision is his sharpness, i.e. The limit ability of the eye to distinguish small objects.

Accommodation - Adaptation of the eye to the vision of various remote items. At accommodation, muscles are reduced that change the crystal curvature. With constant excessive curvature of lens, light rays are refracted before the retina and as a result occurs. myopia . If the crystal curvature is insufficient, the light rays focus on the retina and arises falnarity. Myopia is developing with an enlarged longitudinal axis of the eye. The parallel rays coming from distant items are collected (focus) ahead of the retina, on which the divergent rays fall and the result is a blurry image. At myopia, glasses are prescribed with scattering bonomed glasses, which reduce the refraction of the rays so much that the image of the objects occurs on the retina. Falnarity is observed with a shortened axis of the eyeball. An image focuses behind the retina. For remediation of vision requires double-screwed glass. The elderity is usually developing after 40 years, when the crystal loses elasticity, hardens and loses the ability to change the curvature, which prevents clearly seeing close distance. The eye loses the ability to the clear vision of the distant items.

Hearing organ and balance.

Hearing analyzer Provides the perception of sound information and its processing in the central sections of the brain cortex.

Peripheral part The analyzers form: internally ear and hearing nerve.

central part Formed by subcortex centers of the middle and intermediate brain and the temporal zone of the bark.

An ear - Parny organ consisting of:

Outdoor ear - includes ear sink, external hearing passage and eardrum.

Middle Ear- consists of a drum cavity, a chain of auditory bones and auditory (Eustachiyeva) pipe. The hearing tube binds the drum cavity with the cavity of the nasopharynx. This ensures pressure alignment on both sides of the eardrum. Hearing bones - hammer, anvil and rapidly bind a drumpatch with a refill oval window leading to the snail. The average ear ensures the transmission of sound waves from a low-density environment (air) to a high density environment (endolymph), in which the receptor cells of the inner ear are located.

Inner ear- Located in the thickness of the temporal bone and consists of a bone and connecting labyrinth located in it. The space between them is filled with perilimph, and the cavity of the interfluent labyrinth is endolymph. In the bone labyrinth distinguish three departments - spell, snail and semicircular channels. To the hearing body applies snail - Spiral channel of 2.5 turns. The snail cavity is separated by a webbed main membrane consisting of a different length fiber. The main membrane contains receptor hair cells. The oscillations of the eardrum are transmitted to the auditory bone. They enhance these oscillations almost 50 times and through oval windows are transmitted to the snail liquid, where the main membrane is perceived by the fibers. Receptor snail cells perceive irritation coming from the fiber and in the auditory nerve transmit it to the temporal zone of the brain cortex. The human ear perceives the sounds with a frequency of 16 to 20,000 Hz.

Equilibrium body or vestibular apparatus Educated two bags filled with liquid and three semicircular channels. Receptor hair cells Located on the bottom and inner side of the bags. They are adjacent to the membrane with crystals - otoliths containing calcium ions. Semicircular channels are located in three mutually perpendicular planes. In the bases of the channels there are hairs cells. The receptors of the olhed apparatus react to acceleration or slowing the straight movement. The receptors of semicircular channels are annoyed with changes in rotational movements. The pulses from the vestibular apparatus on the vestibular nerve enter the CNS. Here are impulses from muscle receptors, tendons, soles. Functionally the vestibular apparatus is associated with a cerebellum responsible for coordination of movements, human orientation in space.

Taste analyzer It consists of receptors located in the taste buds of the language, the nerve conductive the impulse in the central department of the analyzer, which is located on the inner surfaces of the temporal and frontal lobes.

Olfactory analyzer It is represented by olfactory receptors located in the mucous membrane of the nose. According to the olfactory nerve, the signal from receptors enters the olfactory zone of the cerebral cortex, which is near the taste area.

Skin analyzer It consists of receptors that perceive pressure, pain, temperature, touch, conducting paths and areas of the skin sensitivity located in the rear central urinet.

Thematic tasks

A1. Analyzer

1) perceives and recycle information

2) conducts a signal from the receptor in the bark of the hemispheres

3) only perceives information

4) only transmits information on the reflex arc

A2. How many links in the analyzer

A3. Sizes and form of the subject are analyzed in

1) the temporal share of the brain

3) the occipital fraction of the brain

2) the frontal share of the brain

4) the parietal fraction of the brain

A4. Sound height is recognized in

1) temporal bark

3) the occipital share

2) frontal share

4) Dark Share

A5. Perceiving light irritation by the body is

2) Crystalik

3) Seth

4) cornea

A6. Perceiving sound irritation by the body is

2) Eustachiev pipe

3) hearing bones

4) oval window

A7. Maximum strengthens sounds

1) external hearing pass

2) Own sink

3) Snail liquid

4) A set of auditory bones

A8. If an image occurs before the retina, it occurs

1) chicken blindness

2) Farcastic

3) Myopia

4) Daltonism

A9. The activity of the vestibular apparatus is regulated

1) Vegetative nervous system

2) visual and auditory zones

3) cores of the oblong brain

4) cerebellar and motor zone of the cortex of the brain

A10. Injection, burns are analyzed in

1) the frontal share of the brain

2) the occipital fraction of the brain

3) anterior central urina

4) rear central urina

IN 1. Select the analyzers departments in which irritation is perceived.

1) skin surface

3) hearing nerve

4) visiting zone of the bark

5) Taste kidneys Language

6) Drumpand

External analyzers

Reception and analysis of information is carried out using analyzers. The central part of the analyzer is some zone in the cerebral cortex. Peripheral part receptors that are on the surface of the body for receiving external information or in the internal organs.

external signals ® receptor® nervous bonds® brain

Depending on the specifics of the received signals distinguish: external (visual, hearing, pain, temperature, olfactory, flavor) and internal (vestibular, pressure, kinesthetic) analyzers.

The main characteristic of analyzers is sensitivity.

The lower absolute threshold of sensitivity is the minimum value of the stimulus to which the analyzer begins to react.

If the stimulus causes pain or impaired analyzer activities - it will be the upper absolute threshold of sensitivity. The interval from a minimum to maximum determines the sensitivity range (for example, for sound from 20 Hz to 20 kHz).

85-90% of all information about the external environment is a person gets through the visual analyzer. Reception and analysis of information is carried out in the range (light) - 360-760 electromagnetic waves. The eye can distinguish between the 7 main colors and more than a hundred shades. The eye is sensitive to the visible range of the spectrum of electromagnetic waves from 0.38 to 0.77 microns. In these boundaries, different wave ranges cause various sensations (colors) when exposed to retina:

0.38 - 0.455 μm - purple;

0.455 - 0.47 μm - blue color;

0.47 - 0.5 μm - blue color;

0.5 - 0.55 microns - green;

0.55 - 0.59 microns - yellow color;

0.59 - 0.61 μm - orange color;

0.61 - 0.77 μm - red.

The greatest sensitivity is achieved at a wavelength of 0.55 microns.

The minimum intensity of the light impact that causes the feeling. Adaptation of the visual analyzer. The time characteristics of the signal perception refers: latent period- time From the signal supply until the feeling of 0.15-0.22 s.; signal detection threshold with greater brightness-0.001 s, with a flash duration-0.1 s.; Incomplete dark adaptation - from a few seconds to several minutes.

Using sound signals, a person receives up to 10% of the information. Hearing signals are used to concentrate human focus, to transfer information to unload the visual system. The peculiarities of the auditory analyzer are:

The ability to be prepared for receiving information at any time;

The ability to perceive sounds in a wide frequency range and highlight the necessary;

The ability to set the location of the sound source with accuracy.

The perceiving part of the auditory analyzer is an ear, which is divided into three departments: outdoor, secondary and internal. Sound waves penetrating into the outer hearing pass, lead to oscillations a drumpatch and through a chain of auditory bones are transmitted to the cavity of the snail of the inner ear. The fluid oscillations in the channel leads to the movement of the fiber of the main membrane in the resonance sounds entering the ear. The fiber oscillations of the snail leads to the movement of the cortiyev cells located in them, a nervous impulse occurs, which is transmitted to the appropriate brain bark departments. Threshold of pain 130 - 140 dB.

The skin analyzer provides perception of touch, pain, heat, cold, vibration. One of the main functions of the skin is protective (from mechanical, chemical damage, from pathogenic microorganisms, etc.). An important function of the skin is its participation in thermoregulation of 80% of the entire organism heat transfer carried by the skin. At high temperature of the outer medium, the skin vessels are expanding (the warmth is enhanced), at low temperatures, the vessels are narrowed (the heat dwindum decreases). The exchange function of the skin consists in participating in the processes of regulation of the general metabolism in the body (water, mineral, carbohydrate). The secretory function is provided with saline and sweat glands. Endogenous poisons, microbial toxins can be released with skin fat.

The olfactory analyzer is intended for perception by a person of various smells (range up to 400 items). The receptors are located on the mucous membrane in the nasal cavity. The conditions of perception of smells are the volatility of the bulk substance, the solubility of substances. Smells can signal a person about violations of technological processes.

To maintain the system of "Human Habitat" in a safe state, it is necessary to coordinate the actions of a person with environmental elements. A person has a direct connection with environmental With the help of senses.

Feeling authorities are complex sensory systems (analyzers), including those perceiving elements (receptors), conductive nervous pathways and the corresponding departments in the brain, where the signal is converted to the sensation.

The main characteristic of the analyzer is the sensitivity that is characterized by the magnitude of the sensation threshold. Distinguish the absolute and differential thresholds of the sensation.

The absolute threshold of sensations is the minimum irritation force capable of causeing the reaction.

The differential threshold of sensations is the minimum value to which you want to change irritation to cause a change in the response. The psychophysical experiments found that the magnitude of sensations varies more slowly than the power of the stimulus.

The time passing from the start of the exposure to the stimulus before the appearance of sensations is called the latent period. Consider some analyzers affecting the conditions for the safe activities of a person.

Spectator analyzer

Approximately from 70 to 90% of the information about the external world, a person gets through vision. Animal of sight - eye - has a high sensitivity. The change in the size of the pupil from 1.5 to 8 mm allows the eye to change the sensitivity hundreds of thousands of times. The retina eye perceives radiation with wavelengths from 380 (purple) to 760 (red) nanometers (billion parts meters).

When ensuring security, it is necessary to take into account the time required for the adaptation of the eye. The adaptation of the visual analyzer is called light adaptation to greater illumination. It requires 1-2 to 8-10 minutes. Eye adaptation to bad illumination (the expansion of the pupil and increase sensitivity) is called tempo adaptation and requires 40 to 80 minutes.

During the period of eye adaptation, human activity is associated with a certain danger. To eliminate the need to adapt or reduce its influence, only one local lighting is not allowed under production conditions. It is necessary to apply measures to protect a person from the blinding effect of light sources and various shiny surfaces, arrange tambura when moving from dark room (for example, in photo laboratories) to normally lit, etc.

Vision is characterized by sharpness, that is, a minimum angle, under which two points are still visible as separate). The acuity of vision depends on the illumination, contrast and other factors. The calculation of graphic accuracy is based on physiological visual acuity.

The binocular field of view covers in the horizontal direction 120-160 degrees, vertically: up - 55-60 degrees, down - 65-72 degrees. The zone of optimal visibility (taken into account when organizing the workplace) is limited to the field: up - 25 degrees, down - 35 degrees, right and left - 32 degrees.

Error estimating the distance to 30 meters on average is 12%.

The sensation caused by a light signal is stored in the eye due to inertia of view to 0.3 seconds. The inertia of view generates a stroboscopic effect - a sense of continuity of movement at a frequency of change of the image about 10 times per second (cinematography), the visual perception of the rotation of the vehicle wheels in the opposite direction and other optical illusions.

The stroboscopic effect can be dangerous. For example, due to its rampant, dangerous situation Can create gas-discharge lighting lamps. Electric voltage fluctuations create fluctuations in light flux. The apparent stopping of the rotating object is observed with the equal frequency of the object of the object and the oscillations of light. When the frequency of light flashes is greater than the number of revolutions of the rotating item, the illusion of rotation is created in the opposite direction from the reality.

Free-sensitive cells (analyzers) eyes in shape resemble small sticks and columns. The retina has about 130 million wands and 6-7 million columns. Thanks to the wands, a person sees at night, but the vision is colorless (acromatic), why and an expression arose: "At night, all the cats are gray." And vice versa - in the afternoon the main role belongs to columns, respectively, the day of sight is color (chromatic).

From position of security, all deviations from the norm in color perception should be taken into account. These deviations include: Color blindness, daltonism and hemerlopia ("chicken blindness"). A man suffering from color blindness perceives all the colors as gray. Daltonism is a private case of color blindness. Daltonists usually do not distinguish red and green colors, and sometimes yellow and purple. They seem gray to them.

Statistically approximately 5% of men and 0.5% of women are a dongeon. Dalton-suffering people cannot work where signaling colors are used for security purposes (for example, drivers). A man suffering from hemerahopia loses the ability to see with a weakened (twilight, night) lighting.

Colors have a different psychophysiological impact on a person, which must be taken into account when securing security and technical aesthetics.

Touch

The skin is a complex organ that performs many protective-defensive functions. It protects the blood from penetrating chemicals into it, preventing the body poisoning, performs the role of the body temperature regulator, protecting the body from overheating and supercooling.

The skin serves as the first protective barrier at the time of touching the current-carrying conductor to the body. Having a large electrical resistance, sometimes tens of thousands, leather, at the first moment, prevents passing electric current Through the internal organs, which makes it possible to include other types of body protection.

Functional disorder 30-50% of the skin, in the absence of special medical care, leads to the death of man.

On the skin there is about 500 thousand points - tactile analyzers that perceive the sensations arising from exposure to the skin surface of various mechanical stimuli (touch, pressure). In addition, on the skin there are unevenly distributed analyzers, perceive pain, heat and cold.

The highest sensitivity on the distal parts of the body (most remote from the axis of the body).

The tactile analyzer has a high ability to spatial localization. Its characteristic feature is the rapid development of adaptation (addiction), i.e. Disappearance of a feeling of touch or pressure. Adaptation time depends on the strength of the stimulus, for various parts of the body it ranges from 2 to 20 seconds. Thanks to adaptation, we do not feel the touch of clothing to the body.

Temperature sensitivity

Temperature sensitivity is characteristic of organisms with a constant body temperature achieved by thermoregulation. Leather temperature is lower than the inner body temperature (approximately z6.6 ° C) and different for individual sites (on the forehead 34-35, on the face of 20-25, on the stomach 34, in the foot footsteps 25-27 ° C).

There are two types of temperature analyzers in the skin: some react only to cold, others - only heat. There are about 30 thousand heat points on the skin and about 250 thousand cold points.

The heating and cold perception threshold is different, for example, thermal points distinguish the temperature difference of 0.2, and the cold points of 0.4 ° C. The time required for the sensation of temperature is approximately 1 second. Temperature analyzers, protecting the body from overheating and supercooling, help maintain a constant body temperature.

Smean

The smell can serve as a signal warning about danger. Everyone knows how dangerous gases. For recognition hazardous gaseswho are not smell, they add special solids to them - odorants. There is no widespread device for measuring the smell strength. However, our nose instantly feels even the smallest fractions of the odorous substances.

A person has about 60 million olfactory cells. They are located in the mucous membrane of the nasal shells on the area of \u200b\u200bapproximately 5 cm2. Cells are covered with a huge amount of hairs with a length of 30-40 angstroms (3-4 nanometers). The area of \u200b\u200btheir contact with fragile substances is 5-7 m2. Nervous fibers are deployed from olfactory cells, sending signals about smelling into the brain.

If the analyzers fall into the analyzers, life-threatening or human health (ether, ammonia alcohol, chloroform, etc.), reflexively slows down or briefly delayed breathing.

Perception of taste

In physiology and psychology, a four-component theory of taste was adopted, according to which the taste has four main types: sweet, salty, sour and bitter. All other taste sensations are a combination of basic types.

The taste is perceived by special cellular formations (similar to the bulbs) located in the mucous membrane of the language.

The distinctive sensitivity of the taste analyzer is quite rude, however, taste sensations play a helpful role in ensuring security.

The flavoring analyzer is about 10 thousand times the rougher smell, the individual perception of taste may vary by up to 20%.

We can use the recommendation of the yogis into an extreme situation: trying to keep stranger, try as long as possible to keep it in my mouth, slowly fastening and listening to your feelings. If an explicit desire to swallow, then try to risk.

Muscular feeling

In man's muscles there are special receptors. They are called proprioceptors (from Latin Proprius - own). They send signals to the brain, reporting in what condition the muscles are. In response, the brain sends impulses coordinating the work of the muscles. Muscular feeling, taking into account the impact of gravity, "works" constantly. Thanks to him, a person takes a more convenient position.

Analyzers - this is functional systemsproviding an analysis (distinction) of irritants acting on the body transforming irritation obtained into a biologically advisable response. The following links can be distinguished in their structure:
- peripheral department - receptors of senses;
- conduction department - nervous paths for which the excitation is transmitted to the bark of large hemispheres of the brain;
- The central department is a section of the cerebral cortex that transforms the resulting irritation into a certain feeling. The modern person has the following analyzers:

Spectator analyzer - The most informative channel (80 - 90% of the information about the world around). The perception of light irritation is carried out with the help of photosensitive cells, sticks and colodes located in the retina of the eye. The disadvantages of the visual channel include the limitations of its field of view (horizontally 120-160 0, vertically 55-70 0) in color perception, the field sizes are narrowed. The visual analyzer has spectral sensitivity. W. modern man Visibility falls on the yellow-green component of the spectrum.

Hearing analyzer The greatest extent complements the information obtained by the visual analyzer, as it has a "circular review." Provides the perception of sound oscillations using sensitive hearing nerve endings. The main parameters of the sound signals are the sound pressure level and frequency (felt as the volume and height of the sound).

Tactile and vibratory sensitivity (touch) It is manifested in action on the skin surface of various mechanical stimuli (touch, pressure). Provides perception of reduction and relaxation of muscles with the help of mechanoreceptors in body tissues.

Temperature sensitivity It is characteristic of organisms with a constant body temperature. There are two types of thermistors in the skin, alone react only to cold, others only for heat. Latent period - 0.25 s

Smeanthe type of sensitivity aimed at the perception of fragile substances with the help of olfactory receptors located in yellow nasal sink epitheliums is called.

Taste analyzer It provides perception of sour, saline, sweet and bitter with chemoreceptors - flavoring bulbs located in the language, in the mucous membrane of the sky, larynx, pharynx, almonds.

Basic characteristic The analyzer is its sensitivity. Not any intensity of the irritant affecting the analyzer causes a feeling. The experiments found that the magnitude of sensations varies more slowly than the power of the stimulus. This empirical psychophysical weber-Fehner Law It is expressed by addiction: E \u003d K * LG (I) + C

Where E is the intensity of sensations, I is the intensity of the stimulus, to and C - constants.

17. The visual analyzer and its capabilities

the visual analyzer provides more than 80% of the information about the external world, is important in ensuring safety, is characterized by the following indicators:

Visual acuity - the ability of separate perception of objects - is controlled by a large number of biocybernetic devices; There is a system that ensures the clarity of the image on the retina by changing the curvature of the lens; In addition, the highlight illumination is regulated by the diameter of the pupil;

The field of view - consists of the central region of binocular vision, which ensures the stereoscopy of perception; its borders in individuals depend on the anatomical factors (the size and form of the nose, age, orbits, etc.); The field of view covers about 240 ° horizontally and 150 ° vertically during normal natural light; Any reduction in illumination, some diseases (glaucoma), defects of blood vessels, lack of oxygen lead to a sharp decrease in sight;

Brightness contrast - sensitivity to it is an important indicator of the visual analyzer; its threshold (the smallest perceived difference in brightness) depends on the level of brightness in the field of view and its uniformity; The optimal threshold is registered with natural light;

Color-perception - the ability to distinguish colors of objects. Color vision is at the same time physical, physiological, psychological phenomenon, which consists in the ability of the eye to react to radiation of various wavelengths, in the specific perception of these radiation. The skin sensation is affected by the wavelength of the radiation, the brightness of the light source, the reflection coefficient or light transmittance object, the quality and intensity of the lighting. Color blindness (daltonism) is a genetic anomaly, but color vision may vary under the influence of the reception of some drugs and under the influence of chemicals. For example, the reception of barbiturates (sleeping pills and sedatives) causes temporary defects in the yellow-green zone; cocainusing sensitivity to blue color and relaxes to red; Caffeine, coffee, coca-cola weaken the sensitivity to blue, enhance the red color; Tobacco causes defects in a red-green zone, especially in red (defects can be permanent).

18 Hearing Analyzer and its characteristics.

The auditory analyzer perceives the sounds that are acoustic oscillations capable of perceived by the hearing body in the range of 16-20000 Hz.

An important characteristic of hearing is its sharpness or hearing sensitivity. It is determined by the minimum value of the sound stimulus causing an auditory feeling. The acuity of hearing depends on the frequency of the perceived beep. The absolute threshold of hearing is the minimum intensity of the sound pressure, which causes an auditory sensation.

With an increase in the intensity of the sound, it is possible to appear an unpleasant sensation, and then pain in the ear. The smallest magnitude of the sound pressure, in which pain occurs, is called the threshold of hearing discomfort. It is an average of 80-100 dB relative to the absolute threshold of hearingness. The intensity of sound exposure determines the volume of the sensation, the frequency is its height. The essential characteristic of the hearing is the ability to differentiate sounds of various intensity by feeling their volume. The minimum value of the sensible difference of sounds according to their intensity is called the differential threshold of the perception of the power of sound. Normally, for the middle part of the frequency range of sound waves, this value is about 0.7-1.0 dB. Since the rumor is a means of communication of people, the ability to perceive speech or speech hearing has a special importance in its assessment. It is especially important in the evaluation of hearing a comparison of speech and tone hearing indicators, which gives an idea of \u200b\u200bthe state of various departments of the auditory analyzer (audiometry). The function of spatial hearing is important, consisting in determining the position and move the sound source in space.

Smell analyzers and taste

Smean- The ability to perceive smells is carried out due to the olfactory analyzer, the receptors of which are sensory nerve cells located in the nasal mucosa.

These cells convert the irritant energy into nervous excitement and transmit it to the olfactory center of the brain. This requires direct contact of the receptor with a fractional molecule. These molecules are precipitated on a small area of \u200b\u200bthe membrane of an olfactory receptor, cause a local change in its permeability for individual ions. As a result, the receptor potential is developing - the initial stage of nervous excitement. A person has different sensitivity to the odorous substances, it is especially high to some substances. For example, ethyl mercaptan is felt by its content in an amount equal to 0.00019 mg per 1 l of air. A complete range of perceived concentrations can cover 12 orders.