1. Organ of smell: structure, functions.

Olfactory organ, organum olfactorium, is a peripheral apparatus of the olfactory analyzer.

It is located in the nasal mucosa, where it occupies the area of ​​the upper nasal passage and the posterosuperior part of the septum, called the olfactory region of the nasal mucosa, regio olfactoria tunicae mucosae nasi.

This section of the nasal mucosa differs from its other sections in its thickness and yellowish-brown color, contains the olfactory glands, glandulae olfactoriae.

The epithelium of the mucous membrane of the olfactory region is called the olfactory epithelium, epithelium olfactorium. It is directly the receptor apparatus of the olfactory analyzer and is represented by three types of cells: olfactory neurosecretory cells, cellulae neurosensoriae olfactoriae, supporting cells, cellulae sustentaculares, and basal cells, cellulae basales.

Olfactory cells are spindle-shaped and end on the surface of the mucous membrane with olfactory vesicles equipped with cilia. The opposite end of each olfactory cell continues into a nerve fiber. Such fibers, connecting into bundles, form olfactory nerves, which, entering the cranial cavity through the openings of the cribriform plate of the ethmoid bone, transmit irritations to the primary centers of smell, and from there to the cortical end of the olfactory analyzer.

2. Organ of taste: structure, functions. organum gustus

The taste organ is a heterogeneous structure. On average, about 2000 taste buds are located in the tissue of the tongue, palate, epiglottis and upper esophagus. Most of them are located in the mucous membrane of the taste bud (papilla vallatae) of the tongue. Taste buds measure 40 microns by 80 microns. In children and young people, each taste bud contains on average 250 taste buds, but in adults there are only 80. 30 - 80 receptor cells form a taste bud. They consist of auxiliary, secondary and sensory cells and are constantly replaced by new ones. The taste receptor does not have its own nerve fibers, but is in contact through synapses with nerve fibers that pass through the tongue. come together and go to cranial nerves VII and IX, and along them to nerve cells in the brain stem.

At the top of the taste bud is a passage that opens on the surface to an opening called the taste pore. Through this hole, liquid enters, which contains substances whose taste must be determined. It washes the sensory cells.

Taste cells are also chemoreceptors. Their functions have not yet been fully explored.

Only four types of taste can be distinguished: sweet, bitter, sour and salty. The combination of these sensations gives us all kinds of taste perception options.

Different types of taste sensations depend on different receptors, which are unevenly distributed over the entire surface of the tongue: sweet is felt at the top, salty and sour are felt on the sides of the tongue, and bitter is felt at the base. The organ of taste has been studied much less well than all other sense organs. Since taste and smell receptors work together, an interesting feature of their cooperation can be observed.

For example, if you have a runny nose, then you cannot fully experience the taste of the food you are eating. 3.Eye: parts. buildings

The human eye is a paired sensory organ (organ of the Visual System) of a person, which has the ability to perceive electromagnetic radiation in the light wavelength range and provides the function of vision. The eyes are located at the front of the head and, together with the eyelids, eyelashes and eyebrows, are an important part of the face. The area of ​​the face around the eyes is actively involved in facial expressions. They even say that “the eyes are the mirror of the soul.” The eye can be called a complex optical device. Its main task is to “transmit” the correct image to the optic nerve.

Cornea- a hole in the iris. Its size usually depends on the light level. The more light, the smaller the pupil.

Lens- the “natural lens” of the eye. It is transparent, elastic - it can change its shape, almost instantly “focusing”, due to which a person sees well both near and far. Located in the capsule, held ciliary girdle. The lens, like the cornea, is part of the optical system of the eye.

Vitreous body- a gel-like transparent substance located in the back of the eye. The vitreous maintains its shape eyeball, participates in intraocular metabolism. Part of the optical system of the eye.

Retina- consists of photoreceptors (they are sensitive to light) and nerve cells. Receptor cells located in the retina are divided into two types: cones and rods. These cells, which produce the enzyme rhodopsin, convert light energy (photons) into electrical energy nerve tissue, i.e. photochemical reaction.

Rods are highly photosensitivity and allow you to see in low light; they are also responsible for peripheral vision. Cones, on the contrary, require more light for their work, but they allow you to see small details (responsible for central vision) and make it possible to distinguish colors. The largest concentration of cones is located in the central fovea (macula), which is responsible for the highest visual acuity. The retina is adjacent to the choroid, but in many areas it is loose. This is where it tends to peel off in various retinal diseases.

Sclera- the opaque outer layer of the eyeball, which passes into the transparent cornea in the front part of the eyeball. 6 extraocular muscles are attached to the sclera. It contains a small number of nerve endings and blood vessels.

Choroid- lines the posterior part of the sclera, the retina is adjacent to it, with which it is closely connected. The choroid is responsible for the blood supply to intraocular structures. In diseases of the retina, it is very often involved in the pathological process. There are no nerve endings in the choroid, so when it is diseased, there is no pain, which usually signals some kind of problem.

Optic nerve- with help optic nerve signals from nerve endings are transmitted to the brain.

4.Eyeball: external structure.

Only the anterior, smaller, most convex part of the eyeball is accessible for inspection - cornea, and the surrounding part; the rest, the larger part, lies deep in the orbit.

The eye has an irregular spherical (almost spherical) shape, with a diameter of approximately 24 mm. The length of its sagittal axis is on average 24 mm, horizontal - 23.6 mm, vertical - 23.3 mm. The average volume of an adult is 7.448 cm3. The weight of the eyeball is 7-8 g.

The size of the eyeball is on average the same in all people, differing only in fractions of millimeters.

There are two poles in the eyeball: anterior and posterior. Anterior pole corresponds to the most convex central part of the anterior surface of the cornea, and posterior pole located in the center of the posterior segment of the eyeball, slightly outside the exit site of the optic nerve.

The line connecting both poles of the eyeball is called outer axis of the eyeball. The distance between the anterior and posterior poles of the eyeball is its largest size and is approximately 24 mm.

Another axis in the eyeball is the internal axis - it connects a point on the inner surface of the cornea, corresponding to its anterior pole, with a point on the retina, corresponding to the posterior pole of the eyeball; its average size is 21.5 mm.

5.Eyeball: membranes.

The eyeball is a sphere with a diameter of about 25 mm, consisting of three membranes. The outer, fibrous membrane consists of an opaque sclera about 1 mm thick, which passes into the cornea in front.

On the outside, the sclera is covered with a thin transparent mucous membrane - the conjunctiva. The middle layer is called the choroid. From its name it is clear that it contains a lot of vessels that nourish the eyeball. It forms, in particular, the ciliary body and the iris. The inner layer of the eye is the retina. The eye also has appendages, in particular the eyelids and lacrimal organs. Eye movements are controlled by six muscles - four rectus muscles and two oblique muscles.

6. Eyeball: fibrous membrane.

Fibrous membrane of the eyeball (tunica fibrosa bulbi oculi,PNA; tunica fibrosa oculi, BNA; tunica externa oculi, JNA) is a fibrous membrane (a layer of connective tissue) that gives the eyeball its shape and also performs a protective function. The fibrous membrane of the eyeball distinguishes two sections: the anterior section - the cornea and the posterior section - the sclera. Both sections of the fibrous membrane have a border between themselves, called a shallow circular groove (lat. sulcus sclerae)

7. Choroid of the eyeball, tunica vasculosa bulbi, a membrane rich in blood vessels, soft, dark-colored from the pigment it contains, lies immediately under the sclera. It distinguishes three sections: the choroid itself, the ciliary body and the iris.

1. Actually choroid choroidea, is the posterior, large section of the choroid. Due to the constant movement of the choroidea during accommodation, a slit-like lymphatic space, spatium perichoroideae, is formed between both membranes.

2. Ciliary body, corpus ciliare, - the anterior thickened part of the choroid, is located in the form of a circular ridge in the area of ​​​​the transition of the sclera to the cornea. With its posterior edge, forming the so-called ciliary circle, orbiculus ciliaris, the ciliary body directly continues into the choroidea. Anteriorly, the ciliary body connects to the outer edge of the iris.

Due to the abundance and special structure of the vessels of the ciliary processes, they secrete liquid - the moisture of the chambers. The other part - accommodative - is formed by an involuntary muscle, m.ciliaris. Circular fibers help accommodation by moving the anterior part of the ciliary processes.

3. Iris, or iris, iris, makes up the most anterior part of the choroid and has the appearance of a circular, vertically standing plate with a round hole called the pupil, pupilla.

The iris plays the role of a diaphragm, regulating the amount of light entering the eye, due to which the pupil narrows in strong light and dilates in weak light. The iris is divided into the anterior surface, facies anterior, facing the cornea, and the posterior, facies posterior, adjacent to the lens

The impermeability of the diaphragm to light is achieved by the presence of a double-layer pigment epithelium on its posterior surface.

8. Retina, or retina, retina,- the innermost of the three membranes of the eyeball, adjacent to the choroid along its entire length up to the pupil and consists of two parts; the external one, containing pigment, pars pigmentosa, and the internal one, pars nervosa, which is divided according to its function and structure into two sections: the posterior one contains photosensitive elements - pars optica retinae, and the anterior one does not contain them.

The boundary between them is marked by a serrated edge, ora serrata, passing at the level of the transition of the choroidea into the orbiculus ciliaris of the ciliary body.

The retina contains light-sensitive visual cells, the peripheral ends of which are shaped like rods and cones. Since they are located in the outer layer of the retina, adjacent to the pigment layer, light rays must pass through the entire thickness of the retina to reach them. The macula contains only cones and no rods

9. The eye consists of two systems: 1) the optical system of the light-refracting midstream and 2) the receptive network system. In the light-refracting medium of the eye one can see: the cornea, the aqueous layer of the anterior chamber of the eye, the crystalline and the corpus corpus. The skin of these midsections shows its own signs of fractured changes. The eye is an organ of vision, a very foldable organ that senses that it receives the action of light. The human eye fights with the singing part of the spectrum. Nowadays, the electromagnetic wave is approximately 400 to 800 nm, so that when afferent impulses arrive in the visual analyzer of the brain, visual sounds are heard.

10. Cameras of the eye.

Anterior chamber of the eye. Posterior chamber of the eye. The space located between the anterior surface of the iris and the posterior side of the cornea is called the anterior chamber of the eyeball, camera anterior bulbi. The anterior and posterior walls of the chamber come together along its circumference in the angle formed by the transition of the cornea into the sclera, on the one hand, and the ciliary edge of the iris, on the other. This angle, angulus iridocornealis, is rounded by a network of crossbars. Between the crossbars there are slot-like spaces. Angulus iridocornealis has an important physiological significance in terms of the circulation of fluid in the chamber, which, through the indicated spaces, is emptied into the venous sinus located nearby in the thickness of the sclera. Behind the iris there is a narrower posterior chamber of the eye, camera posterior bulbi, which also includes the spaces between the fibers of the ciliary girdle; behind it is limited by the lens, and on the side by the corpus ciliare. Through the pupil, the posterior chamber communicates with the anterior one. Both chambers of the eye are filled with a transparent liquid - aqueous humor, humor aquosus, the outflow of which occurs into the venous sinus of the sclera.

11. Aqueous humor of the eye

Aqueous humor of the chambers of the eye (lat. humor aquosus) is a transparent liquid that fills the anterior and posterior chambers of the eye. Its composition is similar to blood plasma, but has a lower protein content.

FORMATION OF WATERY MOISTURE

Aqueous humor is formed by special non-pigmented epithelial cells of the ciliary body from the blood.

The human eye produces from 3 to 9 ml of aqueous humor per day.

CIRCULATION OF AQUEOUS MOISTURE

Aqueous humor is formed by processes of the ciliary body, secreted into the posterior chamber of the eye, and from there through the pupil into the anterior chamber of the eye. On the anterior surface of the iris, the aqueous humor rises upward due to the higher temperature, and then descends from there along the cold posterior surface of the cornea. Next, it is absorbed in the corner of the anterior chamber of the eye (angulus iridocornealis) and through the trabecular meshwork enters Schlemm’s canal, from there again into the bloodstream.

FUNCTIONS OF AQUEOUS HUMOR

Aqueous humor contains nutrients (amino acids, glucose) that are necessary to nourish the nonvascularized parts of the eye: lens, corneal endothelium, trabecular meshwork, anterior vitreous.

Due to the presence of immunoglobulins in the aqueous humor and its constant circulation, it helps remove potentially dangerous factors from the inside of the eye.

Aqueous humor is a light-refracting medium.

The ratio of the amount of aqueous humor formed to that removed determines intraocular pressure.

12. Additional structures of the eye (structurae oculi accessoriae) include:

Eyebrow (supercilium);

Eyelids (palpebrae);

External muscles of the eyeball (musculi externi bulbi oculi);

Lacrimal apparatus (apparatus lacrimalis);

Connective shell; conjunctiva (tunica conjunctiva);

Orbital fasciae (fasciae orbitales);

Connective tissue formations, which include:

Periosteum of the orbit (periorbita);

Orbital septum (septum orbitale);

Vagina of the eyeball (vagina bulbi);

Suprapyllous space; episcleral space (spatium episclerale);

Fatty body of the orbit (corpus adiposum orbitae);

Muscular fasciae (fasciae musculares).

19. Outer ear(auris externa) - part of the hearing organ; is part of the peripheral section of the auditory analyzer. The outer ear consists of auricle and external auditory canal. Auricle formed by elastic cartilage of complex shape, covered with perichondrium and skin, contains rudimentary muscles. Its lower part - the lobe - is devoid of a cartilaginous skeleton and is formed by fatty tissue covered with skin. The auricle has depressions and elevations, among which are the helix, the stalk of the helix, the antihelix, the tubercle, the tragus, the antitragus, etc. The auricle, narrowing funnel-shaped, passes into the external auditory canal, which has the shape of a tube ending at the eardrum. External auditory canal with consists of two sections: membranous-cartilaginous outside and bone inside: in the middle of the bone section there is a slight narrowing. The membranous-cartilaginous section of the external auditory canal is displaced downward and anteriorly in relation to the bone. In the lower and anterior walls of the membranous-cartilaginous section of the external auditory canal, the cartilage is not located as a solid plate, but in fragments, the gaps between which are filled with fibrous tissue and loose fiber; the posterior and upper walls do not have a cartilaginous layer. The skin of the auricle continues onto the walls of the membranous-cartilaginous section of the external auditory canal; the skin contains hair follicles, sebaceous and sulfur glands. The secretion of the glands mixes with the sloughing cells of the stratum corneum of the epidermis and forms earwax, which dries out and is usually released in small portions from the ear canal when the lower jaw moves. The walls of the bony part of the external auditory canal are covered thin skin(approximately 0.1 mm), it contains neither hair follicles nor glands, its epithelium extends to the outer surface of the eardrum.

20. pinna 21. external auditory canal. See question 19

22.Middle ear(lat. auris media) - part of the auditory system of mammals (including humans), developed from the bones of the lower jaw and ensures the conversion of air vibrations into vibrations of the fluid that fills the inner ear. The main part of the middle ear is the tympanic cavity - a small space with a volume of about 1 cm³ located in the temporal bone. There are three auditory ossicles: the malleus, the incus and the stirrup - they transmit sound vibrations from the outer ear to the inner ear, simultaneously amplifying them.

The auditory ossicles, as the smallest fragments of the human skeleton, represent a chain that transmits vibrations. The handle of the malleus is closely fused with the eardrum, the head of the malleus is connected to the incus, and that, in turn, with its long process, is connected to the stapes. The base of the stapes closes the window of the vestibule, thus connecting to the inner ear.

The middle ear cavity is connected to the nasopharynx through the Eustachian tube, through which the average air pressure inside and outside the eardrum is equalized. When external pressure changes, the ears sometimes become blocked, which is usually resolved by yawning reflexively. Experience shows that ear congestion is solved even more effectively by swallowing movements or by blowing into a pinched nose at this moment (the latter can cause pathogenic bacteria to enter the ear from the nasopharynx).

23.Tympanic cavity It has a very small size (volume about 1 cm3) and resembles a tambourine placed on its edge, strongly inclined towards the external auditory canal. There are six walls in the tympanic cavity: 1. The lateral wall of the tympanic cavity, paries membranaceus, is formed by the tympanic membrane and the bony plate of the external auditory canal. The upper dome-shaped expanded part of the tympanic cavity, recessus membranae tympani superior, contains two auditory ossicles; the head of the malleus and the incus. In case of disease, pathological changes in the middle ear are most pronounced in this recessus. 2. The medial wall of the tympanic cavity is adjacent to the labyrinth, and therefore is called labyrinthine, paries labyrinthicus. It has two windows: a round window, the window of the cochlea - fenestra cochleae, leading into the cochlea and covered by the membrana tympani secundaria, and an oval window, the window of the vestibule - fenestra vestibuli, opening into the vestibulum labyrinthi. The base of the third auditory ossicle, the stapes, is inserted into the last hole. 3. The posterior wall of the tympanic cavity, paries mastoideus, bears an elevation, eminentia pyramidalis, for placing m. stapedius Recessus membranae tympani superior continues posteriorly into the cave of the mastoid process, antrum mastoideum, where the air cells of the latter open, cellulae mastoideae. Antrum mastoideum is a small cavity protruding towards the mastoid process, from the outer surface of which it is separated by a layer of bone bordering the posterior wall of the auditory canal immediately behind the spina suprameatica, where the cave is usually opened during suppuration in the mastoid process.

4. The anterior wall of the tympanic cavity is called paries caroticus, since the internal carotid artery is close to it. In the upper part of this wall there is an internal opening of the auditory tube, ostium tympanicum tubae auditivae, which gapes widely in newborns and young children, which explains the frequent penetration of infection from the nasopharynx into the middle ear cavity and further into the skull. 5. The upper wall of the tympanic cavity, paries tegmentalis, corresponds to the tegmen tympani on the anterior surface of the pyramid and separates the tympanic cavity from the cranial cavity. 6. Bottom wall, or bottom, of the tympanic cavity, paries jugularis, faces the base of the skull adjacent to the fossa jugularis.

The chambers of the eye are closed spaces connected to each other and filled with intraocular fluid. There are rear eye camera and the front, reminiscent of baglaza ru. Their connection in a healthy eye is carried out using.

Structure

Anterior chamber of the eye

Posterior chamber of the eye

Borders: anteriorly - the iris, posteriorly - the vitreous body. Also, from the outside, the posterior chamber is limited by the ciliary body, and from the inside by part of the equator of the lens. As the site obaglaza.ru suggests, the entire space is filled with connecting threads between the lens capsule and the ciliary body. When tensioned or relaxed, the ligaments react and change the shape of the lens (accommodation). This allows you to maintain excellent visibility at different distances.

Functions

The main tasks of the eye chambers, according to obaglaza.ru, are to provide life support to tissues, moisturize them and participate in conduction to the retina and refraction of light together with the cornea. The intraocular fluid and cornea refract the rays and act as a lens, focusing the image of objects on the retina.

Diseases

Pathological processes of the eye chambers can be divided into:

1. Congenital
   • violation of the structure or absence of the anterior chamber angle;
   • blockade of the angle by embryonic tissues;
   • anterior attachment of the iris.
2. Purchased

• blockade of the angle (by the iris, pigment, etc.);
• decreased depth (iris bombardment);
• different depths of subsequent injuries;
• accumulation of purulent masses or hemorrhages in the chamber space;
• precipitates on corneal tissue;
• adhesions as a result of inflammatory processes;
• recession of the anterior chamber angle.

Diagnostics

The obaglaza website emphasizes that by examining the structure of the eye it is possible to identify and prevent eye diseases of various origins. The main diagnostic methods are:

1. Transmitted light imaging;
2. Biomicroscopy;
3. Gonioscopy;
4. Diagnostics using ultrasound;
5. Tomogram of the anterior part of the eye;
6. Measuring the depth of the anterior chamber;
7. Measurement inside eye pressure;
8. A thorough study of the production and degree of outflow of intraocular fluid.

Vision is the most important way of perceiving the world around us. If the quality of eye function decreases, this inevitably causes discomfort and reduces the quality of life. Apple features play important role in how a person sees, how clearly and brightly.

Features of the structure of the eye

The human eye is a unique organ that has a special structure and properties. Thanks to this, we see the world in the colors to which we are accustomed.

There is a special fluid inside the eye that continuously circulates. The eyeball itself is divided into two parts:

1. Anterior chamber of the eye (photo presented in the article).
2. Posterior chamber of the eye.

If the functioning of the organs is not impaired by injury or disease, then the intraocular fluid spreads unhindered throughout the eyeball. The volume of a given liquid is a constant value. From a functionality point of view, the front part plays a more important role. Where is the anterior chamber of the eye located and why is it important?

Structure

To understand the structural features of the anterior part of the eye, it is important to understand the location of the anterior chamber. Considering the issue from an anatomical point of view, it becomes obvious that the anterior chamber of the eye is located between the cornea and the iris.

In the center of the eye (opposite the pupil), the depth of the anterior chamber can reach up to 3.5 mm. On the sides of the eyeball, the anterior chamber tends to narrow. This structure makes it possible to detect possible pathologies area of ​​the eye, due to changes in the depth or angles of the anterior chamber of the eye.

Intraocular fluid is produced in the posterior chamber, after which it enters the anterior chamber and flows back through the angles (peripheral parts of the anterior chamber of the eye). This circulation is achieved due to different pressures in the ophthalmic veins. This process plays a key role in the quality of human vision. Despite the apparent simplicity, difficulties often arise, which from a medical point of view is considered a disease.

Anterior chamber angle

Balance is necessary; the human body is designed in such a way that most processes are interconnected. The angles of the anterior chamber act as a drainage system through which ocular fluid passes from the anterior chamber to the posterior chamber. Where the anterior chamber of the eye is located is now clear; its corners are located on the border between the cornea and the sclera, where the iris also passes into the ciliary body.

The drainage system of the eyeball involves: the following departments:

• Scleral venous sinus.
• Trabecular diaphragm.
• Collecting tubules.

Only the correct interaction of all parts makes it possible to stably regulate the outflow of ocular fluid. Any deviations can lead to increased eye pressure, the formation of glaucoma and other eye pathologies.

Where is the anterior chamber of the eye located? In the photos given in the article you can see the structure of this organ.

Role of the anterior chamber

The basic function of the eyeball cameras became clear. This is the regular production and renewal of intraocular fluid. In this process, the role of the anterior chamber is as follows:

1. Normal outflow of intraocular fluid from the anterior chamber, which guarantees its stable renewal.
2. Light conductivity and light refraction, which allows light waves to penetrate the eyeball and reach the retina.

The second function largely also lies in the posterior chamber of the eye. Considering that all parts of the organ are closely interconnected and ensure constant interaction, it is difficult to divide them into specific tasks.

Possible eye diseases

The anterior chamber of the eye is located close to the surface, which makes it vulnerable not only to internal pathologies, but also to external damage. At the same time, it is customary to divide eye pathologies into congenital and acquired.

Congenital changes in the anterior chamber of the eye:

1. Complete absence corners of the anterior chamber.
2. Incomplete resorption of embryonic tissues.
3. Incorrect attachment to the iris.

Acquired pathologies can also become a problem for vision:

1. Blocking of the angles of the anterior chamber of the eye, which does not allow intraocular fluid to circulate.
2. Incorrect dimensions of the anterior chamber (uneven depth, shallow anterior chamber).
3. Accumulation of pus in the anterior chamber.
4. Hemorrhage into the anterior chamber (which often occurs due to external trauma).

The anterior chamber of the eye is located in the organ in such a way that when the lens or choroid is detached, its depth will change. In some cases, this process is controlled by a doctor when treating concomitant diseases. In other situations, it is necessary to seek help to determine the cause of discomfort and visual impairment.

Diagnostics

Modern medicine does not stand still, constantly improving methods for diagnosing complex and subtle pathologies.

So, to determine the condition of the anterior chamber of the eye, the following measures are used:

1. Slit lamp examination.
2. Holding an apple.
3. Microscopy of the anterior chamber of the eye (helps determine the presence of glaucoma).
4. Pachymetry, or determining the depth of the chamber.
5. Measuring intraocular pressure.
6. Study of the composition of intraocular fluid and the quality of its circulation.

Based on the data obtained, the doctor is able to make a diagnosis and prescribe treatment. It is important to understand that with pathologies of the anterior or posterior chamber of the eye, the quality of vision suffers, since any pathologies interfere with the formation of a clear image on the retina.

Treatment methods

The treatment method that will be chosen for the patient depends on the diagnosis. In most cases, the patient prefers to be treated on an outpatient basis, refusing hospitalization. Modern medicine allows therapy and even surgery to be carried out in this way.

It is important that the anterior chamber of the eye is close to the surface and is exposed to external factors and the ingress of additional dust microparticles. In some cases, wearing a special bandage or compress is recommended, but this decision must be made by a doctor. Self-medication is dangerous and can lead to irreversible deterioration and loss of vision.

In medicine, there are several main approaches to treatment:

1. Drug therapy.
2. Surgery.

Medicines may be prescribed by your doctor. It is important to take into account all the patient’s health features, which will help avoid allergic reactions and complications.

Eye microsurgery is a complex operation that requires high professional precision. Surgical intervention scares the patient, but given where the anterior chamber of the eye is located, it is important to remember that the decision to operate is made only in the most advanced cases. More often it is possible to get rid of pathologies using other methods.

Possible complications

As you can see in the photo above, the anterior chamber of the eye is in direct interaction with the outside world. It absorbs the effects of light rays, helping them to refract correctly and be reflected on the retina.

If the outer part of the eye is exposed mechanical damage or internal pathologies, this will inevitably affect the quality of vision. Often, hemorrhage occurs in the anterior chamber due to injury or surges in intraocular pressure. If such things are one-time in nature, then they pass quickly enough, causing only temporary discomfort.

If the pathologies are more serious (for example, glaucoma), then this can irreversibly damage the quality of vision up to its complete loss. Regular examination by an ophthalmologist is important, which will allow timely detection of abnormalities.

The cavity of the eye contains light-conducting and light-refracting media: aqueous humor that fills its anterior and posterior chambers, the lens and the vitreous body.

Anterior chamber of the eye (camera anterior bulbi) is a space bounded by the posterior surface of the cornea, the anterior surface of the iris and the central part of the anterior lens capsule. The place where the cornea meets the sclera and the iris meets the ciliary body is called the anterior chamber angle ( angulus iridocornealis). In his outer wall there is a drainage (for aqueous humor) system of the eye, consisting of the trabecular meshwork, scleral venous sinus (Schlemm's canal) and collector tubules (graduates). Through the pupil, the anterior chamber freely communicates with the posterior one. In this place it has the greatest depth (2.75-3.5 mm), which then gradually decreases towards the periphery (see Fig. 3.2).

Posterior chamber of the eye (camera posterior bulbi) is located behind the iris, which is its anterior wall, and is bounded externally by the ciliary body and posteriorly by the vitreous body. Inner wall forms the equator of the lens. The entire space of the posterior chamber is penetrated by ligaments of the ciliary girdle.

Normally, both chambers of the eye are filled with aqueous humor, which in its composition resembles blood plasma dialysate. Aqueous humor contains nutrients, in particular glucose, ascorbic acid and oxygen, consumed by the lens and cornea, and removes waste metabolic products from the eye - lactic acid, carbon dioxide, exfoliated pigment and other cells.

Both chambers of the eye contain 1.23-1.32 cm3 of fluid, which is 4% of the total contents of the eye. The minute volume of chamber moisture is on average 2 mm3, the daily volume is 2.9 cm3. In other words, complete exchange of chamber moisture occurs within 10 hours.

There is an equilibrium between the inflow and outflow of intraocular fluid. If for any reason it is disrupted, this leads to a change in the level of intraocular pressure, upper limit which normally does not exceed 27 mm Hg. (when measured with a Maklakov tonometer weighing 10 g). The main driving force that ensures the continuous flow of fluid from the posterior chamber to the anterior chamber, and then through the angle of the anterior chamber outside the eye, is the pressure difference in the eye cavity and the venous sinus of the sclera (about 10 mm Hg), as well as in the said sinus and anterior ciliary veins.

Lens (lens) is a transparent semi-solid avascular body in the form of a biconvex lens, enclosed in a transparent capsule, with a diameter of 9-10 mm and a thickness (depending on accommodation) of 3.6-5 mm. The radius of curvature of its anterior surface at rest of accommodation is 10 mm, the posterior surface is 6 mm (with a maximum accommodation stress of 5.33 and 5.33 mm, respectively), therefore, in the first case, the refractive power of the lens averages 19.11 diters, in the second - 33.06 ditr. In newborns, the lens is almost spherical, has a soft consistency and a refractive power of up to 35.0 diters.

In the eye, the lens is located immediately behind the iris in a depression on the anterior surface of the vitreous body - in the vitreous fossa ( fossa hyaloidea). In this position, it is held by numerous vitreous fibers, which together form the suspensory ligament (ciliary girdle).

Posterior surface of the lens. like the anterior one, it is washed by aqueous humor, since it is separated from the vitreous body almost along its entire length by a narrow gap (retrolental space - spaiium retrolentale). However, along the outer edge of the vitreous fossa, this space is limited by the delicate annular ligament of Wieger, located between the lens and the vitreous body. The lens is nourished by metabolic processes with chamber moisture.

Vitreous chamber of the eye (camera vitrea bulbi) occupies the posterior part of its cavity and is filled with the vitreous body (corpus vitreum), which is adjacent to the lens in front, forming a small depression in this place ( fossa hyaloidea), and throughout the rest of its length it is in contact with the retina. The vitreous body is a transparent gelatinous mass (gel-type) with a volume of 3.5-4 ml and a weight of approximately 4 g. It contains large quantities hyachuronic acid and water (up to 98%). However, only 10% of water is associated with the components of the vitreous body, so fluid exchange in it occurs quite actively and, according to some data, reaches 250 ml per day.

Macroscopically, the vitreous stroma itself is isolated ( stroma vitreum), which is pierced by a vitreous (clockets) canal, and the hyaloid membrane surrounding it from the outside (Fig. 3.3).

The glassy stroma consists of a fairly loose central substance, in which there are optically empty zones filled with liquid ( humor vitreus), and collagen fibrils. The latter, becoming denser, form several vitreal tracts and a denser cortical layer.

The hyaloid membrane consists of two parts - anterior and posterior. The border between them runs along the dentate line of the retina. In turn, the anterior limiting membrane has two anatomically separate parts - lenticular and zonular. The boundary between them is the circular hyaloidocapsular ligament of Wieger. durable only in childhood.

The vitreous body is tightly connected to the retina only in the region of its so-called anterior and posterior bases. The first refers to the area where the vitreous body is simultaneously attached to the epithelium of the ciliary body at a distance of 1-2 mm anterior to the serrated edge (ora serrata) of the retina and 2-3 mm posterior to it. The posterior base of the vitreous body is the zone of its fixation around the optic nerve head. It is believed that the vitreous body also has a connection with the retina in the area of ​​the macula.

Glassy(clockets) channel (canalis hyaloideus) of the vitreous body begins in a funnel-shaped expansion from the edges of the optic disc and passes through its stroma towards the posterior capsule of the lens. The maximum channel width is 1-2 mm. In the embryonic period, the vitreous artery passes through it, which is empty by the time the child is born.

As already noted, there is a constant flow of fluid in the vitreous body. From the posterior chamber of the eye, the fluid produced by the ciliary body enters the anterior part of the vitreous through the zonular fissure. Next, the fluid that has entered the vitreous body moves to the retina and the prepapillary opening in the hyaloid membrane and flows out of the eye both through the structures of the optic nerve and through the perivascular spaces of the retinal vessels.

3578 0

Intraocular fluid

Intraocular fluid or aqueous humor (humor aquosus) is contained in the perivasal, perineural fissures, suprachoroidal and retrolental spaces, but its main depot is the anterior and posterior chambers of the eye.

Its composition includes about 99% water and a very small amount of proteins, of which in childhood and adulthood the predominant fractions are albumin, glucose and its breakdown products, vitamins B1, B2, C, hyaluronic acid, enzymes - proteases, traces of oxygen, trace elements Na , K, Ca, Mg, Zn, Cu, P, as well as C1, etc. The composition of chamber moisture corresponds to blood serum. The amount of aqueous humor in early childhood does not exceed 0.2 cm3, and in adults it reaches 0.45 cm3.

Due to the fact that the main component of the intraocular fluid is water, and it is filtered from the chambers of the eye mainly through the angle of the anterior chamber, it is absolutely necessary to know the topography of these areas of the eye.

Front camera

Front camera limited in front by the posterior surface of the cornea, along the periphery (in the corner) by the root of the iris, the ciliary body and corneoscleral trabeculae, behind by the anterior surface of the iris, and in the pupillary region by the anterior capsule of the lens.

By the time of birth, the anterior chamber is morphologically formed, but in shape and size it differs significantly from the chamber in adults. This is explained by the presence of a short anteroposterior (sagittal) axis of the eye, the unique shape of the iris (funnel-shaped) and the spherical shape of the anterior surface of the lens. It is important to know that the posterior surface of the iris in the area of ​​its pigment fimbria is in close contact with the interpupillary region of the anterior lens capsule.

In a newborn, the depth of the anterior chamber in the center (from the cornea to the anterior surface of the lens) reaches 2 mm, and the angle of the chamber is sharp and narrow; by one year the chamber increases to 2.5 mm, and by 3 years it is almost the same as in adults, i.e. .e. about 3.5 mm; The camera angle becomes more open.

Anterior chamber angle

Anterior chamber angle formed by corneal-scleral trabecular tissue, a strip of sclera (scleral spur), the ciliary body and the root of the iris (see Fig. 6). Between the trabeculae there are gaps - the spaces of the iridocorneal angle (fountain spaces), which connect the angle of the chamber with the venous sinus of the sclera (Schlemm's canal).

Venous sinus of the sclera- This is a circular sinus, the boundaries of which are the sclera and corneoscleral trabeculae. Dozens of tubules extend from the sinus in a radial direction, which anastomose with the intrascleral network, pierce the sclera in the limbus in the form of aqueous veins and flow into the epicleral or conjunctival veins.

The venous sinus of the sclera is located in the intrascleral groove. During the prenatal period of development, the angle of the anterior chamber is covered with mesodermal tissue, but by the time of birth this tissue is largely resorbed.

A delay in the reverse development of the mesoderm can lead to an increase in intraocular pressure even before the birth of the child and the development of hydrophthalmos (dropsy of the eye). The state of the anterior chamber angle is determined using gonioscopes, as well as various goniolenses.

Rear camera

Rear camera the eye is limited in front by the posterior surface of the iris, the ciliary body, the ciliary belt and the extrapupillary part of the anterior capsule of the lens, behind - posterior capsule lens and vitreous membrane.

Due to the uneven surface of the iris and ciliary body, various shapes lens, the presence of space between the fibers of the ciliary girdle and the depression in the anterior part of the vitreous body, the shape and size of the posterior chamber can be different and change with pupil reactions and dynamic shifts ciliary muscle, lens and vitreous body at the moment of accommodation.

The outflow of intraocular fluid from the posterior chamber goes mainly through the pupil area into the anterior chamber and then through its angle into the facial vein system.

Eye socket

Eye socket (orbita) is a protective bone skeleton, a receptacle for the eye and its main appendages (Fig. 13).

Rice. 13. Orbit.
1 - top orbital fissure; 2 - small wing of the main bone; 3 - visual opening; 4 - posterior ethmoidal opening; 5 - orbital plate of the ethmoid bone; 6 - anterior lacrimal ridge; 7 - lacrimal bone with posterior lacrimal ridge; 8 - fossa of the lacrimal sac; 9 - nasal bone; 10 - frontal process upper jaw; 11 - lower orbital margin; 12 - orbital surface of the upper jaw; 13 - suborbital groove; 14 - infraorbital foramen; 15 - inferior orbital fissure; 16 - orbital surface of the zygomatic bone; 17 - round hole; 18 - large wing of the main bone; 19 - orbital surface of the frontal bone; 20 - upper orbital margin [Kovalevsky E.I., 1980].

She was educated with inside front part sphenoid bone, part of the ethmoid bone, the lacrimal ossicle with a recess for the lacrimal sac and the frontal process of the upper jaw, in the lower part of which there is an opening for the nasolacrimal bone canal.

The lower wall of the orbit consists of the orbital surface of the upper jaw, the orbital process palatine bone and zygomatic bone. At a distance of approximately 8 mm from the edge of the orbit there is an inferior orbital groove - a fissure (f. orbitalis inferior), in which the inferior orbital artery and the nerve of the same name are located.

The outer, temporal, thickest section of the orbit is formed by the zygomatic and frontal bones, as well as the large wing of the sphenoid bone. Finally, top wall The orbit is represented by the frontal bone and the lesser wing of the sphenoid bone. In the upper outer corner of the orbit there is a recess for the lacrimal gland, and on the inner third of its edge there is a superior orbital notch for the nerve of the same name.

In the upper internal part of the orbit, at the border of the paper plate (lamina papiracea) and the frontal bone, there are anterior and posterior ethmoidal openings through which the arteries and veins of the same name pass. There is also a cartilaginous block through which the tendon of the superior oblique muscle is thrown.

In the depths of the orbit there is a superior orbital fissure (f. orbitalis inferior) - a place for the oculomotor (n. oculomotorius), nasociliary (n. nasociliaris), abducens (n. abduoens), trochlear (n. trochlearis), frontal (n. frontalis), lacrimal (n. lacrimalis) nerves and exit into the cavernous sinus of the superior ophthalmic vein (v. ophthalmica superior), (Fig. 14).

Rice. 14. Base of the skull with the eye socket opened and prepared.
1 - lacrimal sac; 2 - lacrimal part of the orbicularis oculi muscle (Horner muscle): 3 - caruncula lacrimalis; 4 - semilunar fold; 5 - cornea; 6 - iris; 7 - ciliary body (lens removed); 8 - jagged line; 9 - plane view of the choroid; 10 - choroid; 11 - sclera; 12 - vagina of the eyeball (Tenon’s capsule); 13 - central retinal vessels in the optic nerve trunk; 14 - hard shell of the orbital part of the optic nerve; 15 - sphenoid sinus; 16 - intracranial part of the optic nerve; 17 - tractus opticus; 18 - a. corotis int.; 19 - sinus cavernosus; 20 - a. opthalmica; 21, 23, 24 - nn. mandibularis ophthalmicus maxillaris; 22 - trigeminal (Gasserian) node; 25 - v. ophthalmica; 26 - fissura orbltalis sup (opened); 27 - a. ciliaris; 28 - n. ciliaris; 29 - a. lacrimalis; 30 - n. lacrimalis; 31 - lacrimal gland; 32 - m. rectus sup.; 33 - tendon m. levatoris palpebrae; 34 - a. supraorbitalis; 35 - n. supraorbitalis; 36 - n. supra trochlears; 37 - n. infratrochlearis; 38 - n. trochlears; 39 - m. levator palpebrae; 40 - temporal lobe brain; 41 - m. rectus internus; 42 - m. rectus externus; 43 - chiasma [Kovalevsky E.I., 1970].

In cases of pathology in this area, they speak of the so-called superior orbital fissure syndrome.

Slightly more medial is the eye opening (foramen opticum), through which the optic nerve (n. opticus) and ophthalmic artery (a. ophthalmica) pass, and at the border of the upper and lower palpebral fissure there is a round opening (foramen rotundum) for the maxillary nerve (n. maxillaris ).

Through these openings the orbit communicates with various parts of the skull. The walls of the orbit are covered with periosteum, which is closely fused with the bone frame only along its edge and in the area of ​​the optic foramen, where it is woven into the hard shell of the optic nerve.

The characteristic features of the newborn's orbit are that its horizontal size is larger than the vertical, the depth of the orbit is small and in shape it resembles a triangular pyramid, the axis of which converges anteriorly, which can sometimes create the appearance of convergent strabismus. Only the upper wall of the orbit is well developed.

The superior and inferior orbital fissures are relatively large, which widely communicate with the cranial cavity and the inferotemporal fossa. Not far from the lower edge of the orbit are the rudiments of the molars. In the process of growth, mainly due to the increase in the large wings of the main bone, the development of the frontal and maxillary sinuses, the orbit becomes deeper and takes on the appearance of a tetrahedral pyramid, its axis moves from a convergent position to a divergent one, and therefore the interpupillary distance increases. By 8-10 years, the shape and size of the eye socket are almost the same as in adults.

When the eyelids are closed, the orbit is closed by the tarso-orbital fascia, which is attached to the cartilaginous framework of the eyelids.

The eyeball from the place of attachment of the rectus muscles to the hard shell of the optic nerve is covered with a thin and elastic fascia (the vagina of the eyeball, Tenon's capsule), separating it from the tissue of the orbit.

The processes of this fascia, extending from the equator of the eyeball, are woven into the periosteum of the walls and edges of the orbit and thus hold the eye in a certain position. Between the fascia and the sclera there is a space filled with episcleral tissue and interstitial fluid, which ensures good mobility of the eyeball.

Pathological changes in the orbit can be caused by anomalies in the shape and size of its bones, as well as result from inflammation, tumors and damage not only to the walls of the orbit, but also to its contents and paranasal sinuses.

Oculomotor muscles

Oculomotor muscles- these are four rectus and two oblique muscles (Fig. 15). With their help, good eye mobility is ensured in all directions.

Rice. 15. Scheme of innervation of the external and internal muscles of the eye and muscle action.
1 - lateral rectus muscle; 2 - inferior rectus muscle; 3 - medial rectus muscle; 4 - superior rectus muscle; 5 - inferior oblique muscle, 6 - superior oblique muscle, 7 - muscle that lifts the eyelid; 8 - parvocellular medial nucleus (center of the ciliary muscle); 9 - small cell lateral nucleus (center of the sphincter of the pupil), 10 - ciliary ganglion, 11 - large cell lateral nucleus; 12 - nucleus of the trochlear nerve; 13- nucleus of the abducens nerve; 14 - center of view in the bridge; 15 - cortical center of gaze; 16 - posterior longitudinal beam; 17 - ciliospinal center, 18 - borderline trunk of the sympathetic nerve; 19-21 - lower, middle and upper sympathetic ganglia; 22 - sympathetic plexus of the internal carotid artery, 23 - postganglionic fibers to the internal muscles of the eye.

The outward movement of the eyeball is ensured by the abductor (external), inferior and superior oblique muscles, and inward by the adductor (internal), superior and inferior rectus muscles. The upward movement of the eye is carried out using the superior rectus and inferior oblique muscles, and the downward movement is carried out by the inferior rectus and superior oblique muscles.

All rectus and superior oblique muscles originate from the fibrous ring located at the apex of the orbit around the optic nerve (annulus tendineus communis Zinni). Along the way, they pierce the vagina of the eyeball and receive tendon sheaths from it.

The tendon of the internal rectus muscle is woven into the sclera at a distance of about 5 mm from the limbus, the external - 7 mm, the lower - 8 mm, the upper - at a distance of up to 9 mm. The superior oblique muscle extends over a cartilaginous block and attaches to the sclera in the posterior half of the eye at a distance of 17-18 mm from the limbus.

The inferior oblique muscle starts from the inferior inner edge of the orbit and is attached to the sclera behind the equator between the inferior and external muscles at a distance of 16-17 mm from the limbus. The place of attachment, the width of the tendon part and the thickness of the muscles vary.