One of the most important properties of all living things is irritable - the ability to perceive information about the internal and external environment using receptors. During this feeling, light, the sound is converted by receptors into nerve impulses, which are analyzed by the central department of the nervous system.

I.P. Pavlov, when studying the perception of the cortex of the brain of various irritations, introduced the concept of the analyzer. Under this term is hidden the entire set of nervous structures, starting receptors and the ending crust of large hemispheres.

In any analyzer, the following departments are distinguished:

• Peripheral - receptor apparatus of sense organs that converts the effect of irritant to nerve impulses
• Conductive - sensitive nerve fibers for which nerve impulses are moving
• Central (cortic) - a plot (share) of the bark of large hemispheres, which analyzes the incoming nerve impulses

Using vision, a person receives most of the environmental information. Since this article is devoted to a visual analyzer, consider its structure and departments. Pay the most attention to the peripheral part - organ of sight, consisting of eyeball and the auxiliary bodies of the eye.

The eyeball lies in the bone capacity - the eyewit. The eyeball has three shells, which we will study in detail:

Most of the cavity of the eye takes vitreous body - Transparent rounded education, which gives an eye with a spherical shape. Also inside is a lens transparent lens, located behind the pupil. You already know that changes in the crystal curvature provide accommodation - the knee setting to the best vision of the object.

But due to what mechanisms there is a change in its curvature? This is possible due to the reduction of the ciliac muscle. Try to bring your finger to the nose, constantly looking at it. You will feel in the eyes of the tension - it is connected with the reduction of the ciliary muscle, thanks to which the lens becomes more convex, so that we can consider a close-based subject.

Imagine another picture. In the office, the doctor says to the patient: "Relax, look at the distance." When looking away, the church muscle relaxes, the lens becomes flattened. I very much hope that the examples given by me will help you mnemonically remember the state of the cereal muscle when viewing objects near and away.

As light pass through the transparent eye environment: the cornea, the fluid of the front chamber of the eye, the lens, the vitreous body - the light is refracted and turns out to be on the retina. Remember that the image on the retina:

• Valid - corresponds to what you actually see
• Reverse - inverted upside down
• Reduced - the dimensions of the reflected "pictures" are proportionally reduced

Conductive and cortical departments of the visual analyzer

We have studied the peripheral department of the visual analyzer. Now you know that wands and columns excited by light effects generate nerve impulses. The nerve cell processes are collected in bundles, which form a visual nerve, leaving the eye and heading to the cortical representation of the visual analyzer.

Nervous impulses in a visual nerve (conduction department) reaches the central department - the occipital fractions of the bark of large hemispheres. It is here that the processing and analysis of the information obtained in the form of nerve impulses.

When falling on the back of the head in the eyes there may be a white flash - "Sparks of the Eyes". This is due to the fact that with the drop mechanically (due to the impact), neurons of the occipital share are excited, the visual analyzer, which leads to a similar phenomenon.

Diseases

Conjunctive - the mucous membrane of the eye, located above the cornea, covering the eye outside and lining the inner surface of the eyelids. The main function of the conjunctiva is the production of tear fluid, moisturizing and wetting the surface of the eye.

As a result allergic reactions Or infections often occurs inflammation of the mucous membrane of the eye - conjunctivitis, which is accompanied by hyperemia (increased blood flow) of the vascular eye - "red eyes", as well as light-in-friendly, tearing and edema age.

Our close attention requires such states as myopia and hyperopia, which can be congenital, and, in this case, related to the change in the shape of the eyeball, or acquired and associated with a disorder of accommodation. Normally, the rays are collected on the retina, but with these diseases everything is different.

With myopia (myopia), the focus of the rays from the reflected item occurs ahead of the retina. In congenital myopia, the eyeball has an extended shape, due to which the rays cannot reach the retina. The acquired myopia is developing due to excessive refractive power of the eye, which may arise due to an increase in the tone of the ciliary muscle.

Mostic people are poorly seen objects located away. For the correction of myopia they require glasses with dowlightened lenses.

With hyperopia (hypermetropy), the focus of rays reflected from the subject is going behind the retina. For congenital distancelessness Eye apple shortened. The acquired form is characterized by flattening the lens and is often accompanied by the elderly.

Falnotherbore people are poorly seen by the latest items. They need glasses with bicon-like lenses for vision correction.

• Read, holding text at a distance of 30-35 cm from eyes
• When writing a light source (lamp) should be on the left side, and, on the contrary, for the left-hander - on the right side
• You should avoid reading lying with weak lighting
• You should avoid reading in transport, as the distance from the text to the eye is constantly changing. The ciliac muscle is reduced, it relaxes - this leads to its weakness, a decrease in the ability to accommodate and deterioration
• Eye injuries should be avoided, as corneal damage cause violation of the refractive ability, which leads to a deterioration

© Bellevich Yuri Sergeevich

This article was written by Bellevich Yuri Sergeyevich and is his intellectual property. Copying, distribution (including by copying to other sites and resources on the Internet) or any other use of information and objects without prior consent of the copyright holder is prosecuted. To obtain the materials of the article and the permission of their use, please refer to

High School N8.

« Human visual analyzer

Student 9A class.

Sherstyukova A.B.

obninsk

Introduction

I. Eyework and Functions

1. Feling

2. Auxiliary systems

2.1. Overall muscle

2.4. Temaful apparatus

3. Shells, their structure and functions

3.1. Outer shell

3.2. Medium (vascular) shell

3.3. Inner sheath (retina)

4. Transparent intraocular environments

5. Perception of light stimuli (light-crossing system)

6. Binocular vision

II. Speed \u200b\u200bnerve

III. Mozgian center

IV. Hygiene view

Conclusion

Introduction

Human eye is an amazing gift of nature. He is able to distinguish the finest shades and the smallest dimensions, well to see the day and not bad at night. And compared to the eyes of animals, has great opportunities. For example, the pigeon sees very far away, but only during the day. Owls and bats are well seen at night, but during the day they are blind. Many animals do not distinguish between a separate color.

Some scientists say that 70% of all information from the world around us we get through the eyes, others are called even a large figure - 90%.

Works of art, literature, unique monuments of architecture became possible thanks to the eye. In the development of space, the organ of vision belongs to a special role. More cosmonaut A. Neoonov noted that in conditions of weightlessness, not a single sense body, in addition, does not give proper information to the perception of a spatial situation.

The emergence and development of the organ of vision is due to the variety of environmental conditions and the inner environment of the body. The light was a stimulus, which led to the emergence of an organ of vision in the animal world.

Vision is ensured by the work of the visual analyzer, which consists of a perceiving part - the eyeball (with its auxiliary apparatus), conducting the paths by which the image perceived by the eye is transmitted at the beginning of the subcortex centers, and then in the bark of the big brain (occipital shares), where are located Higher visual centers.

I. The structure and function of the eye

1. Feling

The eyeball is located in the bone container - a red-having width and a depth of about 4 cm; In shape, it resembles a pyramid of four faces and has four walls. In the depths of the eyelid, there are upper and lower and nourish-eye cracks, a visual channel, through them nerves, artery, veins. The eyeball is located in the front of the orbit, separated from the rear section of the connective membrane - the vagina of the eyeball. In the backyard it is located optic nerve, muscles, vessels, fiber.

2. Extractive systems

2.1. Overall muscle.

In the movement, the eyeball leads four straight (top, bottom, medial and lateral) and two oblique (upper and lower) muscles (Fig. 1).

Fig.1. Overall muscles: 1 - medial straight line; 2 - upper straight; 3 - upper oblique; 4 - lateral straight line; 5 - Lower straight; 6 - lower oblique.

Medial straight muscle (reducing) turns the eye of the bed, the lateral - knutrice, the upper straight moves upwards and knutrice, the upper oblique is the book and the duck and the lower oblique - up and the duck. Eye movements are provided by the innervation (excitation) of these muscles with eye, block-shaped and discharge nerves.

2.2. Eyebrows

Eyebrows are designed to protect the eyes from droplets of sweat or rain flowing from the forehead.

2.3. Century

These are movable dampers covering in front of the eyes and protect them from external influences. The skin of the age is thin, under it there is a loose subcutaneous tissue, as well as the circular muscle of the eye, providing the clamp of the eyelids with a dream, blinking, and grinding. In the thuscale of the century there is a connecting plate - cartilage, giving them the form. In the edges of the eyelids grow eyelashes. In centuries are located sebaceous glandsThanks to the secret of which it creates a sealing bag seal when closing the eye. (Conjukiwa is a thin connecting sheath that widespread the back surface of the eyelids and the front surface of the eyeball to the cornea. With closed eyelids, the conjunctiva forms a conjuncture bag). It warns the eye clogging and drying the cornea during sleep.

2.4. Temaful apparatus

The tear is formed in the tear gland located in the upper gender corner of the orbit. The tear gland's output ducts falls into the conjunctival bag, protects, nourishes, moisturizes the cornea and conjunctival. Then, on the lacrimal routes, it enters the nasal cavity through the nasal duct. With a constant blowing age on the cornea, a tear is distributed, which supports its humidity and flushes small foreign bodies. The secret of the tear glands acts as a disinfectant liquid.

3. Shells, their structure and functions

The eyeball is the first important component of the visual analyzer (Fig. 2).

The eyeball is not quite the right spherical shape. It consists of three shells: external (fibrous) capsule, consisting of a cornea and sclera; medium (vascular) shell; internal (mesh shell, or retina). The shells surround the inner cavities (cameras) filled with transparent water melted moisture ( intraocular fluid), and internal transparent refractive media (crystal and vitreous body).

Fig.2. Eyeball: 1 - cornea; 2 - front camera eye; 3 - crystal; 4 - sclera; 5 - vascular shell; 6 - retina; 7 - optic nerve.

3.1. Outdoor shell

This is a fibrous capsule, which causes the form, the tour (tone) of the eye, protects its contents from external influences and serves as a place of attachment of the muscles. It consists of a transparent cornea and an opaque sclera.

The cornea is a refractive medium when light rays come into the eye. There is a lot of nervous endings in it, so the hit of even small suture on the cornea causes pain. The cornea is dense enough, but has good insight. Normally, it does not contain blood vessels, it is covered with epithelium.

The scler is an opaque part of the fibrous eye capsule having a bluish or white color. Overhead muscles are attached to it, the vessels and nerves of the eye are passing through it.

3.2. Medium (vascular) shell.

Vascular provides meals with an eye, it consists of three departments: iris, ciliary (ciliary) body and a vascular shell itself.

Rainbow - The most forefront of the vascular shell. It is located behind the cornea so that there remains free space between them - the front chamber of the eye filled with transparent water moisture. Through the cornea and this moisture, the iris is clearly visible, its color determines the color of the eyes.

In the center of the iris, there is a round hole - the pupil, the dimensions of which vary and regulate the amount of light falling inside the eye. If there are a lot of light, the pupil is narrowing if it is not enough - expands.

The ciliary body is the middle part of the vascular shell, the continuation of the iris, it has a direct impact on the lens, thanks to the bundles of its composition. With the help of ligaments, a lens capsule is stretched or relaxed, which changes its shape and refractive force. From the refractive strength of the lens, the ability of the eye to see near or away. The clarity body is like an iron of the internal secretion, since it takes place from the blood of a transparent water heater, which enters the eye and feeds all its internal structures.

Actually vascular shell - This is the back of the middle shell, it is located between the scleria and the retina, consists of the vessels of different diameters and blood supply to the retina.

3.3. Inner sheath (retina)

The retina is a specialized brain tissue made on the periphery. With the help of retina vision is carried out. The retina is a thin transparent shell adjacent to the vascular shell at all over it up to the pupil.

4. Transparent intraocular environments.

These environments are designed to transmit light rays to the retina and their refraction. Light rays, having loved in roghorian pass through the front chamber filled with transparent water moisture. The front camera is located between the cornea and iris. A place where the cornea goes into the scler, and the iris into the ciliary body is called rainbound corner (The angle of the anterior chamber), through which waterproof moisture is exposed (Fig. 3).

Fig.3. Rainbow corneal angle: 1 - conjuctiv; 2 - sclera; 3 - venous sinus sclera; 4 - cornea; 5 - Rainbow Corneal Angle; 6 - iris; 7 - crystal; eyelash belt; 9-ciliary body; 10 - front camera eye; eleven - rear camera eyes.

The next refractive medium of the eye is crystalik. . This is an intraocular lens, which can change its refractive force depending on the tension of the capsule due to the work of the ciliary muscle. Such an adaptation is called accommodation. There are violations of vision - myopia and hyperopia. Myopia is developing due to an increase in lens curvature, which may occur with improper metabolism or impaired hygiene of view. Falcastness arises due to a decrease in crustacea. Crystalik does not have vessels, nerves. It does not develop inflammatory processes. It has many proteins that can sometimes lose their transparency.

Vitreous body - Lighting medium of the eye located between the lens and the eye. This is a viscous gel that supports the shape of the eye.

5. Perception of light stimuli (light-crossing system)

Light causes irritation of light-sensitive retinal elements. In the retina there are photosensitive visual cells that have the form of sticks and colodes. The sticks contain the so-called visual purple or Rhodopsin, thanks to which the sticks are excited by very quickly weak twilight light, but can not perceive the color.

Vitamin A is involved in the formation of Rhodopsin, with its lack of "chicken blindness" develops.

Columns do not contain a visual purple. Therefore, they are slowly excited and only bright light. They are able to perceive the color.

In the retina there are three types of colums. Some perceive the red color, others - the green, third - blue, depending on the degree of excitement of the colodes and the combination of irritation perceived various other colors and their shades.

In the eye of a person there are about 130 million chopsticks and 7 million colodes.

Right opposite the pupil in the retina is the round shape of the yellow spot - the stain of the retina with a hole in the center, which focuses a large number of colums. This segment of the retina is the area of \u200b\u200bthe best visual perception and determines the eye sharpness, all other sections of the retina - a field of view. From the photosensitive elements of the eye (sticks and colodes), nerve fibers are deployed, which, connecting, form a visual nerve.

Retina spectator nerve called disk of the 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.

6.Binular vision.

To obtain one image in both eyes of the line of view, it is converged at one point. Therefore, depending on the location of the subject, these lines when looking at distant items diverge, and on the close - converge. Such an adaptation (convergence) is carried out by arbitrary muscles of the eyeball (straight and oblique). This leads to a single stereoscopic image, to the embossed vision of the world. Binocular vision makes it possible to also determine the mutual location of items in space, visually judge their remoteness. When looking with one eye, i.e. With monocular vision, it is also possible to judge the remoteness of objects, but less exactly than with binocular vision.

II. Speed \u200b\u200bnerve

The visual nerve is the second important component of the visual analyzer, it is a conductor of light irritation from the eye to the auditorium and contains sensitive fibers. Figure 4 shows the conducting paths of the visual analyzer. 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 visual channel, along with the same nerve of the other side, forms the cross (chiam). Between both retina there is a link through a nervous beam going through the front angle of the cross.

After crossing, the visual nerves continue in visual tracts. The optic nerve is like a brainstanty, rendered on the periphery and associated with the nuclei of the intermediate brain, and through them with the crust of large hemispheres.

Fig.4. Ways of the visual analyzer: 1 - field of view (nasal and temporal halves); 2 - eyeball; 3 - optic nerve; 4 - visual cross; 5 - a visual tract; 6 - subcortical visual assembly; 7 - visual radiation; 8 - visual core centers; 9 - eyelary corner.

III. Mozgian center

The auditorium is the third important part of the visual analyzer.

According to I.P. Pavlov, the center is the brain end of the analyzer. Analyzer is a nervous mechanism, the function of which is to decompose the entire complexity of the external and inner world into separate elements, i.e. carry out analysis. From the point of view, I.P.Pavlova, the brainstall, or the cortical end of the analyzer, has no strictly outlined boundaries, but consists of a nuclear and diffused part. The "kernel" presents a detailed and accurate projection in the crust of all elements of the peripheral receptor and is necessary for the implementation of higher analysis and synthesis. "Scattered elements" are on the periphery of the nucleus and can be scattered away from it. They carry out simpler and elementary analysis and synthesis. Under the damage to the nuclear part, the scattered elements can up to a certain extent to compensate for the feed function of the nucleus, which is of great importance for the restoration of this function in humans.

Currently, the entire brain crust is considered as a solid perceiving surface. The bark is a set of circular ends of analyzers. Nervous impulses from the external environment of the body enter the cortical ends of the analyzers of the outside world. An auditorium analyzer belongs to the analyzers of the outside world.

The core of the visual analyzer is in the occipital share - fields 1, 2 and 3 in fig. 5. On the inner surface of the occipital share in the field 1 ends the visual path. The retina of the eye is designed here, and the visual analyzer of each hemisphere is associated with the retina of both eyes. When defeating the core of the visual analyzer, blindness occurs. Above the fields 1 (in Fig. 5), the field 2 is located, with the defeat of which the vision is saved and only the visual memory is lost. Even above - field 3, with the defeat of which the orientation is lost in an unusual setting.

IV. Hygiene view

For normal operation, it is necessary to protect them from different mechanical influences, read in a well-lit room, holding a book at a certain distance (up to 33-35 cm from the eyes). The light should fall on the left. It is impossible to be close to the book, since the lens in this position is long in convex condition, which can lead to the development of myopia. Too bright lighting is harmful, destroys light-crossing cells. Therefore, for example, Stalalem. Welders and persons of other similar professions are advised to wear dark protective glasses during operation.

You can not read in moving transport. Due to the instability of the position of the book, the focal length is changing all the time. This leads to a change in crystal curvature, a decrease in its elasticity, as a result of which the ciliary muscle is weakened. When we read lying, the position of the book in your hand towards my eyes is also constantly changing, the habit of reading is harmful.

Vision disorder may also arise due to lack of vitamin A.

Stay in nature, where a large horizon is provided - a wonderful vacation for the eyes.

Conclusion

Thus, the visual analyzer is a complex and very important tool in human vital activity. No wonder, the science of eyes, called ophthalmology, stood out into an independent discipline as due to the importance of the functions of the organ of vision and due to the characteristics of the methods of its survey.

Our eyes provide perception of the magnitude, shape and color of objects, their mutual location and the distance between them. Information about the changing outer world man gets the most over the visual analyzer. In addition, the eyes still decorate the face of a person, no wonder they are called the "soul mirror".

The visual analyzer is very significant for a person, and the problem of preserving good vision is very relevant for a person. Comprehensive technical progress, universal computerization of our life is an additional and hard load on our eyes. Therefore, it is so important to observe hygiene of view, which, in essence, is not as difficult: not to read in uncomfortable for the eyes of the conditions, take care of the eye in production through protective glasses, work on a computer with interruptions, do not play games that can lead to eye injury etc.

Due to the vision, we perceive the world as it is.

Literature

1. Big Soviet Encyclopedia.

GL. A.M. Prokhorov., Ed.3-E.S. " Soviet Encyclopedia", M., 1970.

2. Dubovskaya L.A.

Eye diseases. Ed. "Medicine", M., 1986.

3. Grees M.G. Lysenkov N.K. Bushkovich V.I.

Human anatomy. Ed.5. Ed. "Medicine", 1985.

4. Rabkin E.B. Sokolova E.G.

Color around us. Ed. "Knowledge", M.1964.

1. What is the analyzer? What parts consists of a virtual analyzer?

Analyzer is a system of sensitive nerve observations that perceive and analyzing annoyance that act per person. The visual analysis - torus consists of 3 parts:

a) the peripheral department - the eye (there are a receptor of the tori, perceive irritation);

b) conduction department - optic nerve;

c) Central Division - brain centers of the occipital shares of the bark of large hemispheres.

2. How does an image of items on the retina arise?

Light rays from items pass through the pupil, the lens and the vitreous body and are assembled on the retina. At the same time on the retina it turns out a valid, reverse, reduced image of the subject. Thanks to the re-work in the core of the occipital share of large hemispheres of the in-formation obtained from the retina (by visual nerve) and receptors of other senses, we perceive objects in their natural position.

3. What violations of vision are most often found? What are the reasons for their occurrence?

The most common violations of vision:

1. Myopia is congenital and acquired in congenital myopia, the eyeball has an extended form, so the image of objects located far from the eye occurs ahead of the retina. With the acquired myopia, it develops due to an increase in the curvature of the lens, which may occur with improper metabolism or violation of the hygiene of the view. Mainees see remote items vague, they need glasses with biconavid lenses.
2. Falnarity is congenital and acquired. With congenital haragility, the eyeball is shortened, and the image of items located close to the eyes occurs behind the retina. Acquired hyperopia occurs due to a decrease in crust scavency and is characteristic of elderly people. Such people see close items vague and cannot read the text, they need glasses with bicon-like lenses.
3. Avitaminosis A leads to the development of "chicken blind-you", while the receptor function of the sticks is disturbed, the twilight vision suffers.
4. Lumbout lens - cataract.

4. What are the rules of hygiene of view? Material from site.

1. You need to read, keeping the text at a distance of 30-35 cm from the eyes, the closer arrangement of the text leads to myopia.
2. With a letter, the lighting should be left for the right and right for the left.
3. When reading in transport, the distance to the text varies in standing, due to the constant jolts, the book is removed from the eye, it is approaching them, which can at-carry viscosity. In this case, the crystal curvature increases, it decreases, and the eyes are wrapped all the time, catching an escair text. As a result, the donkey believes the ciliac muscle and the worsening of vision comes.
4. It is impossible to read lying, the position of the book in his hand on the eye to the eyes is constantly changing, its illumination is insufficient, it harms sight.
5. Eyes must be protected from injuries. Eye injuries are the cause of tormenting cornea and blindness.
6. Conjunctivitis - inflammation of the mucous membranes lawsuit. In the purulent stage can cause blindness.

5. What functions perform the senses?

With the help of various sense organs in humans different kinds Sensings: light, sound, smelt, temperature, pain, etc. Thanks to the senses, a holistic perception of the OK-rushing world is carried out. Obtaining from the organs of the senses of the in-formation on the state and change of external and internal medium, its processing, the preparation of the organism on its basis of the pro-gram of the body.

Didn't find what you were looking for? Use the search

On this page, material on the themes:

• hygiene view
• vision visual analyzer
• how the image occurs on the retina
• eye hygiene summary
• central Spectatical Analysis

Analyzer is not just an ear or eye. It is a combination of nerve structures that include a peripheral, perceiving machine (receptors) transforming irritation energy into a specific excitation process; conductive part represented by peripheral nerves and conductive centers, it transmits the resulting excitation into the bark of the brain; The central part is the nervous centers located in the cerebral cortex, analyzing the information received and forming the corresponding feeling, after which a certain tactic behavior is produced. With the help of analyzers, we objectively perceive the outside world as it is.

1. The concept of analyzers and their role in the knowledge of the surrounding world.

4. Visual analyzer.
5. Skin hygiene.
6. Types of leather and base of skin care.
7. Skin analyzer.
8. List of literary.

Files: 1 file

Volga State Socio-Humanitarian Academy

Student Essay 1 Course
On anatomy and age physiology

"Analyzers. Hygiene skin, auditory and visual analyzers. "
Faculty of psychology

institutions of Education of PGSGA

Lecturer: Gordievsky A.Yu.

Performed: Holunova Tatiana

2013

Subject: "Analyzers. Hygiene skin, auditory and visual analyzers. "

1. The concept of analyzers and their role in the knowledge of the surrounding world.

2. Sensitivity of the auditory analyzer.

3. Hygiene of the child's hearing organ.

4. Visual analyzer.

5. Skin hygiene.

6. Types of leather and base of skin care.

7. Skin analyzer.

8. List of literary.

1. The concept of analyzers and their role in the knowledge of the surrounding world

The body and the outside world is a single integer. The perception of the environment of us occurs with the help of the senses or analyzers. An Aristotle was described five major feelings: vision, hearing, taste, smell and touch.

Analyzer is not just an ear or eye. It is a combination of nerve structures that include a peripheral, perceiving machine (receptors) transforming irritation energy into a specific excitation process; conductive part represented by peripheral nerves and conductive centers, it transmits the resulting excitation into the bark of the brain; The central part is the nervous centers located in the cerebral cortex, analyzing the information received and forming the corresponding feeling, after which a certain tactic behavior is produced. With the help of analyzers, we objectively perceive the outside world as it is. This is a materialistic understanding of the issue. On the contrary, the idealistic concept of the theory of knowledge of the world is nominated by the German physiologist I. Myulller, which formulated the law of specific energy. The latter, according to I.Muller, is laid and formed in our senses and this energy, we perceive in the form of certain sensations. But this theory is not true, as it is based on the action of inadequate for this irritation analyzer. The intensity of the stimulus is characterized by the threshold of the sensation (perception). The absolute threshold of sensations is the minimum intensity of the intensity that creates a corresponding feeling. Differential threshold is the minimum difference in the intensities that is perceived by the subject. This means that the analyzers are able to give a quantitative assessment of the growth of the sensation towards its increase or decrease. So, a person can distinguish a bright light from the less bright, give an estimate of the sound at its height, tone and volume. The peripheral part of the analyzer is represented by either special receptors (nipples of the language, olfactory hairs cells), or a complex organ (eye, ear). The visual analyzer provides perception and analysis of light irritation, and the formation of visual images. The cortical department of the visual analyzer is located in the occipital shares of the cortex of large hemispheres of the brain. The visual analyzer is involved in the implementation of written speech. The auditory analyzer provides perception and analysis of sound irritation. The cortical department of the auditory analyzer is located in the temporal area of \u200b\u200bthe cortex of large hemispheres. With the help of the auditory analyzer, oral speech is performed. The speech analyzer provides perception and analysis of information coming from speech bodies. The cortical department of the spectavatic analyzer is located in a post-central overhang of the crust of large hemispheres. With the help of reverse impulses coming from the cortex of the brain to the motor nerve endings in the muscles of respiratory and articulation organs, the activity of the speech apparatus is regulated.

2. Sensitivity of the auditory analyzer

The human ear can perceive the range of sound frequencies in fairly wide limits: from 16 to 20,000 Hz. The sounds of the frequencies below 16 Hz are called infrasounds, and above 20,000 Hz - ultrasound. Each frequency is perceived by certain areas of auditory receptors that react to a certain sound. The greatest sensitivity of the auditory analyzer is observed in the medium-sized region (from 1000 to 4000 Hz). Speech uses sounds within 150 - 2500 Hz. Hearing bones form a system of levers, with the help of which the transmission of sound oscillations from the hearing aid air is improved to the perilimph inner ear. The difference in the magnitude of the base of the fusing (small) and the area of \u200b\u200bthe eardrum (large), as well as in a special way of the articulation of seats acting like levers; The pressure on the oval window membrane increases 20 times or more than on the eardrum, which helps to enhance the sound. In addition, the system of auditory bones can change the strength of high sound pressures. As soon as the sound wave pressure approaches 110 - 120 dB, the nature of the seed movement is significantly changing, the pressure of the stirrup on the round window of the inner ear is reduced, protects the hearing receptor from long sound overloads. This change in pressure is achieved by reducing the muscles of the middle ear (the muscles of the hammer and austrix) and the amplitude of the oscillations of the stirrups decreases. The auditory analyzer is capable of adapting. The prolonged effect of sounds leads to a decrease in the sensitivity of the auditory analyzer (adaptation to the sound), and the absence of sounds - to its increase (adaptation to silence). Using the auditory analyzer, you can relatively define the distance to the sound source. The most accurate estimate of the speed of the sound source occurs at a distance of about 3 m. The direction of sound is determined by the binaural hearing, the ear, which is closer to the sound source, perceives it earlier and, therefore, more intensely sound. This determines the delay time to another ear. It is known that the thresholds of the auditory analyzer are not strictly constant and fluctuate in large limits in humans depending on the functional state of the body and the action of environmental factors.

There are two types of sounding oscillations - air and bone sound conductivity. With the air conductivity of the sound, the sound waves are captured by the ear shell and are transmitted to the outer auditory passage on drumpatchAnd then through the system of hearing bones of perilimph and endolymph. A man with air conduction is able to perceive sounds from 16 to 20,000 Hz. The bone conductivity of the sound is carried out through the bones of the skulls, which also have sound-conducting. Air conduction sound is better expressed than bone.

3. Human hearing hygiene

One of the skills of personal hygiene is to follow the tidwing of his face, in particular the ears - should also be given to the child if possible. Wash ears, follow their cleanliness, delete selection, if any.

In a child with a thread from the ear, even seemingly the most insignificant, the inflammation of the outer auditory pass is often developing. About eczema, the reasons for which are often purulent average otitis, as well as mechanical, thermal and chemical damage caused during the purification of the auditory passage. The most important thing at the same time is the observance of the Hygiene of the ear: you need to clean it from pus, to dry in case of injection of droplets with an average purulent otitis, lubricate the auditory passage by vaseline oil, cracks - tincture of iodine. Usually doctors prescribe dry heat, blue light. The prevention of the disease is mainly in the hygienic content of the ear with a purulent average otitis.

It is necessary to clean your ears once a week. Pre-drip in each ear for 5 minutes a 3% solution of hydrogen peroxide. Sulfur masses softened and turn into a foam, they are easy to remove them. With the "dry" cleaning, a risk is a risk to push a part of the sulfur masses into the depths of the outer auditory passage, to the eardrum (sulfur tube is formed).

I need to pierce the uhulie the ear only in cosmetic cabinets so as not to cause infection of the auricle and its inflammation.

Systematic stay in a noisy atmosphere or short-term, but very intensive impact of sound can lead to hearing loss. Further ears from too loud sounds. Scientists found out that the long-term impact of loud noise harms hearing. Strong, sharp sounds lead to the rupture of the eardrum, and constant loud noises cause the loss of elasticity of the eardrum.

In conclusion, it is necessary to emphasize that the hygienic education of the baby in kindergarten and at home, of course, is closely related to other types of education - mental, labor, aesthetic, moral, i.e. with the education of the person.

It is important to observe the principles of systematic, graduality and sequence of formation of cultural and hygienic skills, taking into account the age and individual characteristics of the baby.

4. Visual analyzer

The organ of view (eye) is the perceiving department of the visual analyzer, it serves to perceive light irritation.

The eye is in the eyeball of the skull. Break the front and rear poles of the eye. The eye includes an eyeball and auxiliary apparatus.

The eyeball consists of a kernel and three shells: outer - fibrous, medium-vascular, internal - mesh.

Eye apple shells.

The fibrous shell is represented by two departments. The front department forms an inspective, transparent and strong curved cornea; The rear-occurring shell (sclera, reminds its color of the ventilation chicken egg). On the border between the cornea and the protein shell, venous sinus passes, according to which venous blood and lymph exposes from the eye. The corneal epithelium passes here in the conjunctival, lining the front of the protein shell.

Behind the scleria is a vascular shell, which consists of three different structures and functions of parts: the vascular shell itself, the ciliary body and iris.

The actual vascular sheath of the loose is connected to the protein, and the lymphatic slots are located between them. It is permeated with a large number of vessels. On the inner surface has a black pigment absorbing light.

The ciliary body, has a roller look. Going inside the eyeball where the protein sheath goes into the cornea. The rear edge of the body goes into a vascular shell itself, and up to 70 cilia processes depart. From them they originate elastic thin fibers, which form a supporting crystal device, or a cireless belt.

In front of the eye, the vascular envelope goes into rainbow. The color of the iris is determined by the amount of coloring pigment (from the blue to dark - brown), which determines the color of the eyes. Between the cornea and iris, there is an anterior eye chamber filled with water-melted moisture.

In the middle of the rainbow shell is a round hole - pupil. We need to regulate the flow of light entering the eye, i.e. Thanks to the cells of smooth muscle tissue, the pupil can expand and driving, passing the amount of light necessary to consider the subject (reflexively narrowing with bright light and expands in the dark due to the muscles of the iris).

Muscular iris fibers have a double direction. Muscle fibers that expand the pupil are located around the pupil edge of the iris, there are circular fibers of the muscle, narrowing pupil.

The mesh shell, or the retina - the adhere to the vitreous body, consists of two parts:

1. Rear - visual - photosensitive, it is a thin and very gentle layer of cells - visual receptors, which are the peripheral separation of the visual analyzer.

2. Front - wilderness and quaduzhny, does not contain photosensitive cells. The border between them is a toothed border, which is located at the level of transition of the vascular shell itself into the crocker.

The place of exit from the eyeball of the optic nerve is called - disk (blind spot), there are no visual receptors. In addition, in the area of \u200b\u200bthe disk in the retina it is entering its own artery and leaves Vienna. Both vessels pass inside the optic nerve.

The visual part of the retina has a complex structure, it consists of 10 microscopic layers (table). The outer layer adjacent to the vascular shell serves a pigment epithelium. The layer of neuroepithelia containing neuroreceptor cells is located behind it.

Retinal receptors are cells in the shape of sticks (125 million) and colodes (6.5 million). They are adjacent to the black vascular sheath. Her fibers surround each of these cells from the sides and rear, forming a black case facing the open side to the light.

Chopsticks - twilight receptors, have a greater sensitivity to the rays of all visible light. Transmit only a black and white image. Each wand consists of an outdoor and inner segments interconnected by a binder department, which is a modified cilia.

In the outer part of the inner segment, there is a basal caller with the basal root, near which centrioles are located. The outer segment - photosensitive - formed by the dual membrane discs, which are the folds of the plasma membrane, to which the visual purple - Rhodopsin is built. The internal segment consists of two parts: ellipsoid (filled with mitochondria) and Mioid (Ribosomes, Golgi complex). From the body of the cell, the process (Akson), ending with a splitting synoptic body, forming tanning synapses.

Columns have less photosensitivity and annoy only bright light and are responsible for colorful vision. There are 3 types of colums sensitive only to blue, green and red light. They are focused mainly in the central part of the retina, in the so-called yellow spot (the place of the best vision is located at a distance of about 4 mm from the disk). In the rest of the retina there are columns, and wands, however, the periphery predominate sticks.

Columns differ from sticks greater magnitude and character of discs. In the distal part of the outer segment of the wisp of the plasma membrane, the semi-conversion, which retain the connection with the membrane, in the proximal part of the outer segment, the disks are similar to the discs of chopsticks. In the ellipsoid domestic segment are elongated mitochondria. The synthesized protein - iodopasin - is continuously transported into the outer segment, where it is embedded in all the discs. In the extended basal part of the colummer cell, a spherical core occurs. From the body of the cell, the axon ends with a wide leg forming synapses.

Before chopsticks and columns are nervous cells that perceive and process information obtained from visual receptors. Neuron axes form a visual nerve.

The core of the eyeball.

Behind the pupil is a crystal, resembling a bicon-like lens.

The crystal is deprived of vessels and nerves, completely transparent and covered by a continuous transparent bag. The crystal is strengthened by the ciliary belt

Between the lens and the iris is the rear eye chamber filled with water-melted moisture. It is highlighted by blood vessels of cilia processes and iris, it is weakly refracting light, its outflow is carried out through venous sinus.

With the help of the surrounding smooth muscles forming the ciliary body, the lens can be changed form: it becomes more convex, then flatter. The lens forms on the rear inner wall of the eye of the mesh shell or the retina reduced inverted image.

The cavity of the eyeball is filled with a transparent substance - a vitreous body. This is a transparent instant pupil, filling the cavity of the eye between the lens and the retina, is involved in maintaining intraocular pressure And eye shapes, tightly connected to the retina.

Auxiliary eye apparatus.

Muscles pass to the eyeball that can move it in different directions. Muscles: Four straight (lateral, medial, upper and lower) and two oblique (upper and lower).

In front of the eye is protected by centuries, eyelashes and eyebrows. The inner surface of the eyelid is lined with a shell - conjunctiva, which continues on the eyeball, covering its free surface. The conjunctiva is limited to a conjunctival bag, which contains a tear liquid, washing the free surface of the eye and having a bactericidal property.

W. inner corner The eyes between the edges of the age are formed by space - a tear lake; At his day is a little elevation - a tear meat. At the edge of both century in this place is located along a small hole - a lacrimal point; This is the beginning of a lacrimal canal.

In the upper corner of the eye on the side of the cheek there is a tear gland. When lowering the movable upper century Iron highlights tears that moisturize, washed and warmed the eye. The lacrimal fluid from the outer upper angle of the eye goes to the lower inner angle and hees into the lacrimal channel, are sent under the skin of the eyelid to the tear bag located on the medial wall of the orbit, and fall into it. The tear bag, narrowing the book, goes into a tear-nasal duct, which takes excess tears into the nasal cavity. The tear liquid contains a bactericidal substance - lysozyme, facilitates the movement of the age, reducing friction.

The fat body fills the space between the walls of the soccer and the eyeball with his muscles. The fat body forms a soft and elastic edge of the eyeball.

Fascia separates the fat body from the eyeball; There remains a slit space between them, which ensures the mobility of the eyeball.

The conduction department begins in the retina. Neurites of its ganglion cells fold into the visual nerves, which entering the visual channels into the skull cavity, form a cross. After crossing each nerve, called now the visual path, envelopes the leg of the brain and is divided into two roots. One of them ends in the upper twolymia. Its fibers go to the belowly located effector nuclei of the trunk and to the cushion of the visual bulb. Another root is sent to the lateral crankshaft. In the pillow and lateral crankshaft, the visual pulses switch to the next neuron, the fibers of which in the composition of the visual radiation are followed: to the cortex of the largest hemispheres (central department).

The visual paths are arranged so that the left part of the field of view from both eyes falls into the right hemisphere of the cortex of the big brain, and the right side of the field of view is in the left. If the images from the right and left eye fall into the corresponding brain centers, they create a single volumetric image. Vision in two eyes is called binocular vision, which provides a clear volume perception of the object and its location in space

5.Gigien skin

In the digital skin analyzer, the most modern and high-precision method, a non-invasive assessment of the human skin state, is the Bioimpeant Method "Bioelectric Impedance Analysis Bia, Skin Analyzer Monitor".

Unfavorable ecology, room with air conditioned air, bad weather conditions (blizzard, hail, rain), pool with poor-quality water, food and drinks, health status and lifestyle, stress at work, change cycles in the body, overdue cosmetics - all this affects Skin condition. Save youth and become even more beautiful, the skin analyzer will help you. This simple mini computer will allow to analyze not only appearance, but also internal state, determine the humidifier of the skin, fatness and softness. With this data you can choose the individual skin care suitable for you.

The time of skin condition data is not more than 10 seconds. Skin analyzer is a powerful tool for evaluating the effectiveness and the result of the effects of cosmetics and the choice of suitable. Is an an indispensable assistant For those whose skin needs permanent special care and care: newborn babies, people suffering from diabetes and many others.

An important positive quality of the analyzer is absolute safety, informativeness, accuracy of results, reliability and simplicity. The analyzer allows us to estimate such skin condition indicators as humidity, dryness, fatness, turgor and the state of the skin epithelium. All indicators are displayed on the LCD display in digital and in the format of histo and icons.

Skin analyzer is suitable for both professional skin care consulting and personal use. This is an important tool for personal care of the skin and will be useful to cosmetologists. Elegant form, maximum portability, small sizes and weight, ease and ease of use makes this device indispensable in the arsenal of means for beauty and youth skin.

The dehydrated is the skin that contains an insufficient amount of water and cannot hold moisture in the upper layer of the epidermis. Dehydrated skin can be not only in dry skin type, but also the skin with a normal and high function of the sebaceous glands! Under the influence of various factors, water entering the cells of the epidermis, quickly evaporates and does not have time to convey useful elements into the skin. Due to the lack of moisture, the skin loses elasticity and wrinkles appear. With the help of the skin analyzer, it is possible to correctly assess the condition of the skin and choose cosmetics and health appliances.

The lesson on the topic "The visual analyzer. Hygiene view. "

Objectives lesson : reveal the structure and value of the visual analyzer; deepen knowledge about the structure and functions of the eye and its parts, show the relationship between the structure and functions, pronounced in this organ; Consider the design mechanism on the retina of the eye and its regulation.

Equipment: Table "Visual Analyzer", PC, Multimedia Projector.

During the classes

Organizing time.

Check of knowledge.

Students are invited to choose the question they can answer.

Questions on the screen.

What bodies belong to the senses?

What does the analysis of external events and internal sensations begins? (from irritation of receptors)

What is called analyzer, what it consists of? (Analyzer \u003d receptor + sensitive neuron + the corresponding cortex zone of a large brain hemispheres.) - Collect the scheme on the board.
(Systems consisting of receptors conducting paths, and centers in the cerebral cortex)

Why for normal operation of any analyzer requires the safety of all its parts?

Why does not the confusion of information received from different analyzers? (Each of the nerve pulses enters into the large brain cortex corresponding to it, there is an analysis of sensations, the formation of images obtained from the senses.)

Why in violation of receptor activities people and animals fall asleep?

What is the importance of analyzers? (In the perception of events around us, the accuracy of the information, contribute to the survival of the body in these conditions).

Studying a new topic.

The game.

2 wishes come out, the eyes are tied, the other plays the role of a dumb, they are offered to take into the hands of any of the items that are in front of it (apple, or two apples of different colors, a tube with cream, etc.). Pupils are proposed to describe the subject that they have in their hands. After the conclusion is made, who can tell more about the subject. What is it? What senses work in this case? Etc.

Conclusion: You can tell about the subject almost everything, without seeing it. But here is the color of the subject, its movement, changes, without an organ of vandine, it is impossible to determine.

What kind of analyzer will we study today?

Children call themselves the answer. (Visual analyzer)

We live with you among the beautiful paints, sounds and smells. But the ability to see the most affects our perception of the world. Another scientists in the ancient world paid attention to this feature. So Plato argued that the first of all the gods arranged light-sound eyes. The gods of the gods, the place in the ancient myths, but the fact remains: it is thanks to the eyes of the eyes with you we get 95% of the information about the world around, they are also calculated by I.M. Sechenov, give a person up to 1000 sensations per minute.

What do such figures mean the XXI century for a person who is accustomed to operate with double-digit degrees, and billion? And yet they are very important for us.

I wake up in the morning and see the face of my native people.

I go out in the morning outside and see the sun or clouds, yellow dandelions among green grass or snow-covered hills around.

And now imagine for a minute that all the beauty of the world around us has disappeared. Rather, this is a blue sky, volcanoes under a white bedspread, the faces of friends, smiling at the spring sun, exist, but somewhere outside of our vision. We can not see this, or see only part ...

You say, thank God, it's not with us. We just do not present our life in the dark.

In general, it should be noted that a person, in contrast to many mammals, was lucky. We have color vision, but do not perceive ultraviolet waves and polarized light, helping to navigate in the fog by some insects.

How are our eyes arranged, what is the principle of their work? Today at the lesson we will part this mystery.

The eye is the peripheral part of the visual analyzer. The organ of view is located in the eyeboard (weighs 6-8 g). It consists of an eyeball with an optic nerve and auxiliary apparatus.

The eye is the most mobile of all organs human organism. He performs permanent movements, even in a state of seeming peace. Movements are carried out by muscles. In total, they are 6, 4 straight and 2 oblique.

Describe the eight through the eyes, repeat 3 times, look at the far right corner, slowly translate the view to the far left corner, repeat 3 times.

Briefly the structure and work of the eye can be described in this way: the flow of light containing information about the subject falls oncornea, then throughfront Camerapasses throughpupil, then throughcrystalik.andthe vitreous body is projected onthe retina, the photosensitive nerve cells of which convert optical information into electrical pulses and the visual nerve is sent to the brain. Having accepted this encoded signal, the brain processes it and turns into perception. As a result - a person sees the items that they are.

Cornea

scleria (Bell shell).

The cornea is a transparent sheath covering the front of the eye. It has a spherical shape and completely transparent. The rays of the light falling on the eye first pass through the cornea, which strongly refracts them. The cornea borders with an opaque outer shell of the eye -scleria (Bell shell).

Front eye camera and rainbow shell

After the horny shell, the light beam passes throughfront chamber eye - space between the cornea and the iris filled with a colorless transparent liquid. Its depth is an average of 3 millimeters. The back wall of the front camera isiris (Iris), which is responsible for the color of the eyes (if the color is blue means, there are few pigment cells in it if the brown is a lot). In the center of the iris is a round hole -pupil .

[Increased intraocular pressure leads to glaucoma]

Pupil

When examining the eye, the pupil seems to us black. Thanks to the muscles in the rainbow shell, the pupil can change its width: lying in the light and expand in the dark. itas if the diaphragm of the camera which automatically narrows and protects the eyes from the receipt of a large amount of light during bright lighting and expands with low light, helping the eye to capture even weak light rays. (Experience: to highlight a lantern one of the students in the eye. What happens)

Crystalik

After passing through the pupil, the beam light hits a lens. It is easy to imagine - this is a lental body,reminding the usual lum . The light can freely pass through a lens, but it is refracted in the same way as the law beam is refracted by the laws, passing through the prism, that is, is rejected to the base. Crystal has Extremely an interesting feature: With the help of ligaments and muscles around it canchange your curvature that in turn changes the degree of refraction. This kind of lens to change its curvature is very important for the visual act. Thanks to this, we can clearly see the outlined items. This ability is calledaccommodation eye. Accommodation is the ability of the eye to adapt to a clear distinction of items located at different distances from the eye.
Accommodation occurs by changing the curvature of the lens surfaces.

(Experience with frame and gauze or with a hole in a sheet of paper).Normal eye is able to precisely focus light from objects located at a distance of 25 cm. To infinity. The refraction of light occurs when it moves from one medium to another, having a different refractive index (studies physics), in particular at the border of the air - the cornea and the surfaces of the lens.(Glass with a spoon in water).

In this regard, the question of how do you think it is harmful to read lying, in transport?

(The book is held in the hands, the support is missing, so the text changes the position all the time. It approaches the eyes, it is removed from them, causing a surgery of the ciliary muscle, changing the curvature of the lens. In addition, part of the page is in the shadow, it turns out to be illuminated too Brightly, this is overwhelmed by the smooth muscles of the iris. But most of all the nervous system is suffering, because the regulation of the width of the pupil and the curvature of the lens is carried out by the middle brain. All this can lead to impairment.

Behind the lens is locatedvitreous body 6. representing a colorless chattering mass. The back of the sclera - the eye bottom - covered mesh sheath (netsyatka ) 7 . It consists of the finest fibers, elderly and representing the branched expirations of the optic nerve.
How do the image of various items occur and perceived by eye?
Refracting to B.optical eye system The cornea, lens and the vitreous body are formed, gives valid, reduced and reverse images of the objects under consideration (Fig. 95) on the retina. Once at the end of the optic nerve, of which the retina consists, the light annoys these endings. For nervous fibers, these irritations are transmitted to the brain, and a person appears a visual sensation: he sees items.

An image of an object arising on the retina of the eye isinverted . The first who proved it by building the course of the rays in The eye system was I. Kepler. To test this conclusion, the French scientist R. Descartes (1596-1650) took the eye bull and, scraping with his back The opaque layer placed in the hole done in the window glass. And immediately on the translucent wall of the eye dna, he saw an inverted image of the picture observed from the window.
Why then we see all the subjects as they are, i.e., untouched? The fact is that the process of view is continuously adjusted by the brain receiving information not only through the eyes, but also through other senses. At one time, the English poet William Blake (1757-1827) was very correctly noticed:
By eye, not an eye
Look at the world knows howground.
In 1896, American psychologist J. Stretton put an experiment on himself. He put on special glasses, thanks to which, on the retina, the images of the surrounding items were not reverse, but straight. And what? The world in the consciousness of Stretton turned over. All items he began to see up his legs. Because of this, there was a mismatch in the work of the eyes with other senses. The scientist has symptoms of marine disease. For three days he felt nausea. However, on the fourth day, the body began to come back in the norm, and on the fifth day Stretton began to feel the same as before the experiment. The brain of the scientist has mastered the new working conditions, and all items he began to see straight. But when he took off his glasses, everything turned over again. After an hour and a half, the vision was restored, and he began to see normal again.
It is curious that such an adaptability is characteristic only for the human brain. When in one of the experiments, turning glasses were put on a monkey, she received such a psychological blow that, having made some incorrect movements and falling, came to a state resembling to whom. Reflexes began to fade, blood pressure and breathing fell frequent and superficial. A person has nothing like that.
Illusions.However, I. human brain It is not always able to cope with the analysis of the image obtained on the retina of the eye. In such cases, ariseillusions - The observable object does not seem like this, what it really is.

Errors (illusions) are distorted, erroneous perceptions . They are detected in the activities of various analyzers. Surrounding illusions are most well known.

It is known that distant items seem small, parallel rails - converge to the horizon, and the same houses and trees seem even lower and below and somewhere at the horizon merge from the ground.

Illusions associated with the phenomenon of contrast. White pieces on a black field seem lighter. In the moonless night, the stars look brighter.

Illusions are used in everyday life. So the dress with longitudinal stripes "narrows" the figure, the dress with transverse stripes "expands". The room is the blue wallpaper seems more spacious than the same room beamed with red wallpaper.

We consider only some illusions. In fact, their significantly more.

Experience with palm (Show photos Causes illusions)

But if our perceptions may be erroneous, is it possible to say that we correctly reflect the phenomena of our world?

Illusions is not a rule, but an exception . If the sense authorities gave an incorrect idea of \u200b\u200breality, living organisms would be destroyed by natural selection. Normally, all analyzers work consistently and check each other in practice. Practice refutes the error.

Vitreous body

After a lens, the light passes throughvitreous body , filling the entire cavity of the eyeball. The vitreous body consists of thin fibers, between which there is a colorless transparent liquid, which has a high viscosity; This liquid resembles molten glass. Hence, his name happened - the vitreous body. Participates in intraocular metabolism.

Retina

The retina is the inner sheath of the eye - the photosensitive apparatus of the eye. Photoreceptors in the retina are divided into two types:columns andsticks . In these cells there is a transformation of light energy (photons) into the electrical energy of the nervous tissue, i.e. Photochemical reaction.

Sticks have high photosensitivity and allow you to see with bad lighting (twilight andblack and white vision), also they are responsible forperipheral vision .

Kolkovka, on the contrary, require more light to work, but they allow you to see small details (responsible forcentral and Color Vision ). The greatest cluster of the colums is located inyellow stain (About it below), which is responsible for the highest visual sharpness.

(Experience with color pencils)

To faster :

At night it is more convenient to walk with a wand.

In the afternoon, laboratory technicians work with kolinks.

The retina is adjacent to the vascular shell, but in many areas is not sure. It is here that she tendssqueeze for various diseases retina.

[Retina is damaged when sugar diabetes, arterial hypertension and other diseases]

Yellow spot

Yellow spot is a tiny, yellowish areanear Central Yameki (Retinal Center) and is located next to the optical axis of the eye. This is the area of \u200b\u200bthe greatest visual acuity, the very "center of view", which we usually prove on the subject.

pay attention toyellow andblind spot .

Summary nerve and brain

Speed \u200b\u200bnerve It passes from each eye to the cavity of the skull. Here, visual fibers do a long and complex path (withperekrestov ) And ultimately end in the occipital part of the cerebral cortex. This area is the highestspectator Center in which the visual image is recreated, which is exactly the subject to the subject matter.

Blind spot

The place of exit from the eye of the optic nerve is calledblind spot . There are no chopsticks, nor kolkok, so the person does not see this place. Why do we not notice the missing piece of pictures? The answer is simple. We look two eyes, so the information for the blind spot is the brain receives from the second eye. Brain in any case "completes" a picture so that we do not see defects.

Blind spot eyes open by french physician edmMariottom In 1668 (remember the school law Boyle Mariott for the perfect gas?) He used his discovery for the original Fun of the Court KingLouis Xiv. . Mariott placed two spectators each opposite each other and asked them to consider some point from the side of the side, then it seemed to everyone that he had no head. The head fell into the sector of the blind spot of the looking eye.

Tryfind in your own "Blind spot" and you.

Close the left eye and look at the letter "O" at a distance30-50 cm . The letter "X" will disappear.

Close the right eye and look at "x". Letter "O" will disappear.

Climbing the eyes to the monitor and giving it, you can observe the disappearance and appearance of the corresponding letter, the projection of which will fall on the area of \u200b\u200bthe blind spot.

Fizkultminutka

Your eyes were a little tired. SHOW SHOULD GAZ AND CHRACT TO 5, then open them and count to 5 again. Repeat 5-6 times. This exercise relieves fatigue, strengthens the muscles of the eyelids, contribute to improved blood circulation and relaxing eye muscles.

Well, our eyes rested, and we go to the next stage of the lesson.

Defects of view.

A person, as in other vertebrates, vision is provided by two eyes. Eye As a biological optical device projects the image on the retina, it pre-processes it and transmits to the brain, which finally interprets the content of the visual image, in accordance with the psychological settings of the observer and its life experience. Due to accommodation, the image of the subjects under consideration is obtained, just on the retina of the eye. This is done if the eye is normal. The eye is called normal if it is in unattended state collecting parallel rays at the point lying on the retina. The most common two lack of eyes is myopia and hyperopia.

Loss of vision and impacts of view cause the restructuring of all systems of the body, thereby forming a person a special perception and a worldship.

Myopia is a defect of view, in which a person clearly sees objects near, while distant items seem blurred. Under myopia, the image of the far object is formed before the retina, and not on the retainer itself. Consequently, a short man sees well at the same time, but he sees the objects away.

Image focusing in front of the retina

The so-called is called such an eye, which has a focus with a calm state of the eye muscle lies inside the eye. Myopia may be due to a large removal of the retinal from the lens compared to the normal eye.

If the item is located at a distance of 25 cm from the nearby eye, then the image of the object is not on the retina, but closer to the lens, the retina is ahead. So that the image turned out to be on the retina, you need to bring the subject to the eye. Therefore, near the portraight eye, the best vision distance is less than 25 cm.

Correction of myopia

This defect can be fixed with concave contact lenses or points. A concave lens of the corresponding power or focal length and is able to transfer the image of the object back to the retina.

Falcastness is a common name for impacts of vision, in which a person sees near objects vague, with blurred vision, and remote objects are good. In this case, the image as well as at myopia is formed behind the retina.

Image focuses behind the retina

The far-sighted is called an eye, which has a focus with the calm state of the eye muscle lies behind the retina. Falcastness may be due to the fact that the retina is located closer to the lens compared to normal eye. An image of the object is obtained behind the retina of such an eye. If the item is removed from the eye, the image hits the retina.

Correction of hyperopia

This deficiency can be corrected using convex contact lenses or points of the corresponding focal lengths.

So, for the correction of myopia, glasses with concave, scattering lenses are used. If, for example, a person wears glasses, the optical strength of which is -0.5 DPTR or -2 DPTR, -3.5 DPTR, then it means a short one.

In glasses for farewell eyes use convex, collecting lenses. Such points may have, for example, optical power +0.5 DPTR, +3 DPTR, +4.25 DPTR.

People and animals have highly developed senses. In order for the information received well to be transmitted and processed, a perfect nerve apparatus is necessary. In many cases, the technique binds certain principles of the nervous system. Therefore, to create accurate tools and devices, nature comes to help.

Conclusion: Compliance with hygiene view is the most important factor in the preservation of eye functions and the necessary condition for maintaining the normal state of the central nervous system.

Fastening the material studied.

1. Test for self-test

1. Structure related to the auxiliary system of the eye:

A. Rogovica
B. Veko
V. Krustalik
Rainbow

2. Structure related to the optical system of the eye:

A. Rogovica
B. Vascular shell
B. Setch
Skilled shell

3. Two-point elastic transparent lens surrounded by the ciliated muscle:

A. Krustalik
B. Pupil
V. Raidzhka
G. vitreous body

4. Retinal function:

A. Refraction of rays of light
B. Nutrition Eyes
B. Perception of Light, transformation to nervous impulses
G. Protection of Eye

5. The color of the eyes attaches:

A. Scheler
B. Crystalik
B. Rainbow Shell
Networks

6. Transparent front of a protein shell:

A. Yellow stain
B. Rainbow
B. Setch
Rogornitsa

7. The venue of the visual nerve:

A. White stain
B. Yellow stain
V. Dark Oblast
Blind spot

8. Inside the eye of the light of light adjusts:

A. Vekto.
B. Seth
V. Krustalik
Pupil

9. A special substance of purple color contained in chopsticks is called:

A. Rhodopsin
B. Opsy
V. Yodopsin
G. Retinen

10. Specify the correct sequence of light from the cornea to the retina:

A. Rogovica, vitreous body, crystal, retina
B. cornea, vitreous body, pupil, crystal, retina
B. Roghorician, Pupil, Crystalik, Glass Body, Retina
City cornea, pupil, crystal, retina

Task at home :

§ 49, 50.

Fill out the table "The structure and function of the organ of sight".