What is the leading sensory organ in humans? The value of the visual analyzer

Sensing is the body’s ability to perceive and recognize various stimuli and respond to them. certain forms reactions. In humans, feeling consists of the perception of sensory information from internal environment body - interoception, which includes proprioception (muscular-joint sense), and from external environment- exteroception, which includes general sensitivity (touch, pain, perception of temperature and pressure), where the stimulus directly affects the perceptual receptor and special types of sensitivity associated with the impact of the stimulus on the sense organs, they are characterized by the ability to perceive the effects of objects remotely. This ability of the body significantly expands its capabilities, but at the same time requires the specialization of nervous structures, their complex structure and interaction with the corresponding parts of the brain. The sense organs can be considered as appendages of the nervous system, which conducts their impulses to the spinal cord and brain.

Thus, the following senses and their organs can be distinguished:

Touch (skin)

The human body is first covered with a thin outer layer of the epidermis, then a thicker layer of the dermis lying underneath. subcutaneous fat. The skin contains mechanoreceptors that are sensitive to touch, including light, pressure and vibration, as well as thermoreceptors that are sensitive to temperature. Nails, hair, sweat and sebaceous glands are appendages of the skin.

Vision (eyes)

Each eyeball is located in the eye socket (socket) on the front of the skull. Light rays enter the eye through the cornea (the transparent area of ​​the outer layer of the eye), which performs the main function of focusing, that is, bringing together rays of light to form an image. The rays then pass through the anterior chamber of the eye and the pupil (the central opening of the iris) before being further finely focused by the lens of the eye. The focused rays form an image on the retina at the back of the eye, where they are converted into electrical impulses by photoreceptor cells, the rods and cones. these impulses are then transmitted through the optic nerve to the cerebral cortex for further processing.

Hearing and balance (ears)

Sound waves reaching the ear pass through its auricle, or outer ear, through the outer ear canal(canal) to the middle ear. These waves vibrate successively, reflecting off the tympanic membrane (middle ear) and on the auditory ossicles (hammer, anvil, and stirrup). These ossicles excite fluid in the inner ear, where the oscillatory basilar membrane at the base of the brain vibrates the organ of Corti, a special organ of the cochlear labyrinth. From here, nerve impulses enter the temporal lobes of the cerebral cortex. vestibular system inner ear, consisting of circumferential canals and elliptical and spherical sacs of the ear labyrinth, controls the position of the head and helps maintain balance and posture.

Sense of smell (nose)

Chemoreceptors in two olfactory membranes - one at the top of each half of the nasal cavity - detect odor molecules. They send nerve impulses to the olfactory bulbs, which are connected to the limbic system of the brain.

Taste (tongue)

Chemoreceptors located on the papillae of the tongue, as well as on the palate, larynx, and nostrils, register various taste sensations: this process is similar to the process of capturing odors. Nerve cells transmit these taste impulses to the thalamus, cortex and brain.

Aristotle once identified five basic senses with the help of which a person exists are: hearing, sight, smell, touch and taste. With the help of these psychological tools, a person receives primary images about the world around him, which are then analyzed by the brain and give an idea of ​​​​the location, as well as further actions organism.

Sense organs can be divided into two groups: remote and tactile. Remote ones include:

• vision ;
• hearing;
• sense of smell.

All images received by these senses are perceived by the human body at a distance, and certain parts of the brain are responsible for perception, as well as for the creation of images, thus creating complex analytical chains.

Tactile senses can be called simpler in their mechanism of action, because touch and taste are primary stage analysis of information by the brain occurs only with direct contact.

Basic characteristics of hearing

Hearing can be called one of the very first sensory senses, which develops and also begins to function even before a person is born.. In the womb, the baby already feels the vibrations of the voices of loved ones, perceives music, noise, as well as gentle tones in the mother's voice. Being born, the little man already has in his memory a certain system of sounds to which he reacts.

organ of hearing, very complex mechanism, which implies a chain of certain actions. Firstly, the human body is capable of hearing sound up to 20 kHz. Secondly, sound enters the body in the form of vibrations, which are perceived eardrum, which in turn begins to vibrate, thereby activating small bones. The hammer-ossicle system, in turn, transmits the vibrations of the eardrum at a certain pace to the inner ear, informing the auditory nerve and then directly to the brain, which reproduces in memory the association corresponding to the received information.

For example, in mobile phone a lot of melodies that correspond to a specific opponent; with each call, a person does not have to look at the phone screen, he already knows the name of the caller, because in his memory there is an association of the melody with a certain person. Or a person hears a clap, he instinctively turns or ducks because sharp sound associated with danger. Many such examples can be given, but the result will be the same, the organ of hearing gives a person the opportunity to reproduce an associated image, which will provide information about what is happening around.

Basic vision characteristics

Like other sense organs, vision begins to develop in the womb, but due to the lack of information, namely visual associations, the organ of vision is considered underdeveloped. Of course, after birth the baby sees, he is able to react to light, to the movement of objects, but there is no information that would correlate the images he sees.

Vision is considered one of the main senses, which gives a person 90% of information about the world around him, and of course the visual system, in comparison with other senses, is considered the most complex. Firstly, visual organ not only reproduces the object, it simultaneously reports a lot of related data, for example, size, color, location, distance, this is the action of the process itself. Then all the data is transmitted to the brain with distortions and errors, which the brain corrects or supplements with the help of already existing information.

For example, upon seeing a ball, a person will say that it is a toy, while the brain will give out information about a round object, let's say red, that can be played with. Unconsciously, in a fraction of a moment, a person will receive processed information based on previously gained experience. Or let's say, on the water surface in the distance, a person sees a small dot, which, having previous visual experience, transforms it into a boat or a ship.

Basic characteristics of the sense of smell

The olfactory organ, as well as other sense organs, develops even in the womb, but naturally, because of the amniotic fluid, the child cannot smell, therefore, by the time of birth it does not have associative information. But after birth, after 10 days, he can smell the presence of his mother nearby by smell.

Of course, the organ of smell cannot be fully called one of the most important feelings, since the information received through the sense of smell, in comparison with other organs, is presented in a small amount. However, even a few molecules on the nasal mucosa can bring back many memories in a person's memory through the association between a smell and a certain one. Perhaps precisely because the sense of smell is closely related to psychological perception. environment it is considered the most mysterious and unpredictable person.

British scientists conducted an interesting experiment. In an unfamiliar environment, which causes discomfort for many people, a person felt an unfamiliar aroma that was not unpleasant and at the same time did not cause delight. As a result, when smelling the previously proposed smell again, a person's mood began to deteriorate, and a breakdown appeared. Through this experiment, it was proved that, despite the fact that the basis of smell is the organism, the result is all psychological associations.

Main characteristics of taste

• The sense of taste develops and also begins to function already in the womb, when the baby tastes the amniotic fluid and tastes the food that the mother takes. Scientists conducted an interesting experiment, two months before the birth, expectant mothers were asked to eat sweets with a certain taste every day, for example, raspberry. After birth, children in a series of proposed berries were the first to recognize the taste of raspberries;
• The perception of taste, as well as smell, is based on chemical reactions organism. As you know, taste is served by the tongue, which is covered with taste buds, and the back wall of the pharynx, palate and epiglottis are also responsible for determining taste. Obtained through the bulbs using the glossopharyngeal and facial nerve in the brain, where there is already a correlation between having experience and, accordingly, the information received;
• For example, it was previously believed that a person can feel only four tastes in certain parts of the tongue, namely bitter, salty, sour and sweet, but modern people are already able to identify a number of other flavors, such as minty, alkaline, tart and metallic. This is not caused by progressive development taste qualities human, but simply by the presence of more information, the mechanism of action remained the same. Taste buds become irritated when exposed to different tastes, and instantly provides relevant information.

Basic characteristics of touch

• Of course, the sense of touch, like other senses, develops even before birth. The baby takes great pleasure in touching himself, the umbilical cord and his mother’s tummy. In this way, he receives information about the environment because the other senses do not help him yet. After birth, the possibilities of touch increase significantly, because now the world you can not only feel, but also see, hear and taste, and therefore assign certain associations;
• The sense of touch is based on tactile sensations, which reproduce the received information using nerve endings located under the skin and in the muscles. It receives information about quality in several ways, by pressure, vibration or feeling the texture of an object. In turn, the brain reproduces the association according to the information received;
• For example, in order to identify a piece of cotton wool by touch, a person does not necessarily have to see it. With the help of a touch, he will feel the softness and send a corresponding signal to the brain, which will reproduce the corresponding image;
• However, with the help of touch or another sense, it is not possible to evaluate the entire world around us; for this, all five senses are needed in a complex, which are a system for reproducing the environment with the help of associative reactions that help a person to exist.

If to speak scientific language, then the human sensory organs are components of the anatomical and physiological system, which, thanks to multiple receptors, allow us to receive and analyze information from the internal and environment.

Definitely, underestimating what is given to man by nature is the greatest stupidity. But what is known about the sensory system, and what facts still remain a mystery to its owners?

People learn about how many sense organs a person has back in the childhood. Usually already at preschool institution kids in game form, fun and playful introduction to the senses. You can ask the little one what is on the top of the animal's head, and what is on the person below the eyes? And he will definitely, even after hesitation, answer that these are ears!

Since the time of Aristotle, 5 human senses have been identified, which transmit flows of information to the brain.

This is about:

They are usually divided into two categories:

1. Remote authorities.
   They are provided by the nose, eyes, ears and here we're talking about about perception. That is, for the brain to receive reliable data, it is enough for a person to contact objects while being at some distance from them.
2. Tactile organs.
   This category includes the remaining major sense organs that provide taste and touch. In this case, it is impossible to do without direct contact with objects, otherwise the analytical chain will be interrupted, and the information will never reach the brain receptors.

It is important for a person that the entire system of sense organs works smoothly and without interruption, and even minor violations can worsen his quality of life.

A little about the mirror of the soul - the eyes

Even Heraclitus of Ephesus designated this sense organ as “a more accurate witness of what is happening than the ears.” What did the eyes do to deserve such a high rank among other organs? In fact, their functions allow a person to receive the most a large number of data about the surrounding world. As for the structure of the eye, it is very complex, and the visual organ consists of many parts.

The outer part of the eye consists of:

Interior:

• vitreous – hyaluronic acid and water refracting light;
• lens– a natural lens responsible for focusing vision;
• retina– a multilayer shell, thanks to which people see in daylight, dim light and distinguish silhouettes in the dark.

In addition, the organ of vision includes several special devices:

• lacrimal, including glands, tubules, nasolacrimal duct and sac.
• muscular - it is difficult to imagine how many muscles are involved in the work of the eyes - straight, oblique, circular, and also providing lifting of the eyelid.

All human senses and their functions are aimed at better perception of the world around us, and the eyes are capable of much. They allow a person to distinguish colors and sense light, have peripheral, central and stereoscopic vision. All images, visible to the eyes, are sent to the brain - main center, which controls absolutely all processes occurring in the body.

Two ears - to listen better...

Another important organ, the influence of which on a person’s life cannot be underestimated. No wonder in folklore and sayings famous people Phrases and aphorisms about ears and hearing are very common: “Women love with their ears”, “In silence you can hear harmony”, “You need to keep your eyes open with children”, etc.

Definitely, the hearing organ deserves special attention, and if you look at its structure, you can understand that this is an amazing part of the body - complex and at the same time functional:

1. Central - includes nerve fibers ending in the temporal lobe of the cerebral cortex.
2. Peripheral area:
   1. the outer ear, consisting of the auricle, auditory canal, and eardrum;
   2. middle ear - including the tympanic cavity, Eustachian tube, mastoid; these are two air cavities connected by the nasopharynx.
3. The inner ear is a bone formation consisting of the vestibule, semicircular canals, bony cochlea and vestibular analyzer.

The ears are able to perceive sounds, sound vibrations, and conduct them and waves to the receptors. Sounds can affect emotional condition person, let alone positive properties the music that a person hears says a lot.

Aristotle also said that “when a person perceives rhythm and melody with the ear, his mental mood changes.” Of course, for this to happen, you need to listen to the “right” melodies that do not cause negativity.

Why is the nose considered the most curious organ?

When considering the human senses, it is impossible to ignore the nose, which allows you to breathe and smell aromas. As for curiosity, it is precisely this that is “poked into someone else’s business”, “torn away from the curious Varvara”, and “bullied” when they become arrogant. What can I say, but in folk aphorisms there is always a grain of wisdom.

The nose is a complex structure consisting of cartilaginous, bone tissue and the skin, and for its full functioning it is important that all parts function. It consists of: root, apex, back, wings, septum and nostrils.

But this outer part organ, which is visible to the naked eye, also the structure of the nose suggests the presence internal cavity. It is located between the eye sockets, the oral cavity and the anterior cranial fossa.

The nasal cavity includes the following sections:

• walls with a ciliated surface - protection from dust and debris;
• olfactory center - located in upper area cavities;
• nasal passages.
• sinuses located near the nose.

This structure of human sensory organs is so thought out by nature that even the nose affects various systems body, in addition to the fact that it makes it possible to smell and breathe:

• is an air filter;
• moisturizes and warms these air masses;
• protects against pathogens contained in the air;
• forms the pitch and timbre of voice notes.

There are many studies devoted to this organ, and sometimes it turns out interesting moments, for example, the most pleasant smells that it is able to capture are the aroma of cut grass, natural coffee and freshly baked buns.

Language helps to experience the taste of life

This is an organ with many receptors capable of distinguishing tastes. It consists of a root, body and apex, and its entire surface is covered epithelial tissue And big amount papillae:

• thread-like;
• mushroom-shaped;
• leaf-shaped;
• trough-shaped;
• salivary.

But in order for a person to experience all the flavor richness of a dish, it is necessary that the nerve endings accept them and carry them to the brain. This is the task facing the glossopharyngeal, vagus nerves and the chorda tympani of the facial nerve.

Language allows people to communicate, protects the body from viral and bacterial pathogens, and in addition to taste, it allows you to feel pain and warmth. According to Hans Georg Gadamer, “Language is the medium that unites the “I” and the rest of the world.”

Modern scientists are studying the effects on the human senses of various external factors– music, gadgets, the Internet, and some consider a person a hostage to his own feelings. But it’s not for nothing that the great William Shakespeare said: “To see and feel is to be, to think, to live.”

Humans are designed to interact with the world around them. A person has five of them:

Organ of vision - eyes -

Hearing organ - ears

Sense of smell - nose -

Touch - skin -

Taste is the tongue.

They all react to external stimuli.

Organs of taste

Humans have a sense of taste. This occurs due to special cells responsible for taste. They are located on the tongue and are combined into taste buds, each of which has from 30 to 80 cells.

These taste buds are located on the tongue as part of the fungiform papillae, which cover the entire surface of the tongue.

There are other papillae on the tongue that detect various substances. There are several types concentrated there, each of which has its own taste.

For example, salty and sweet defines the tip of the tongue, bitter is its base, and sour is the lateral surface.

Olfactory organ

The olfactory cells are located in the upper part of the nose. Various microparticles enter the nasal passages on the mucous membranes, due to which they begin to contact with the cells responsible for smell. This is facilitated by special hairs that are located in the thickness of the mucus.

Pain, tactile and temperature sensitivity

The organs of this species are very important, because it allows you to protect yourself from various dangers of the outside world.

Special receptors are scattered across the surface of our body. Cold react to cold, to heat - thermal, to pain - painful, to touch - tactile.

Most of the tactile receptors are located in the lips and on the fingertips. There are much fewer such receptors in other parts of the body.

When you touch something, tactile receptors are irritated. Some of them are more sensitive, others less, but all the information collected is sent to the brain and analyzed.

The human senses include the most important organ - vision, thanks to which we receive almost 80% of all information about the outside world. The eye, oculomotor muscles, lacrimal apparatus, etc. are elements of the organ of vision.

The eyeball has several membranes:

The sclera, called the cornea

The choroid, passing in front into the iris.

Inside it is divided into chambers filled with jelly-like transparent contents. Cameras surround the lens - a transparent disk for viewing objects that are close and far.

Inner side eyeball, which is opposite to the iris and cornea, has light-sensitive cells (rods and cones) that convert into an electrical signal that enters the brain through the optic nerve.

Lacrimal apparatus designed to protect the cornea from microbes. The lacrimal fluid continuously washes and moisturizes the surface of the cornea, providing it with sterility. This is facilitated by episodic blinking of the eyelashes.

The human sense organs include the hearing organ, which consists of three components - the inner, middle and outer ear. The last one is auditory concha and ear canal. Separated from it by the eardrum is the middle ear, which is a small space with a volume of about one cubic centimeter.

The eardrum and inner ear contain three small bones called the malleus, stapes, and incus, which transmit sound vibrations from the eardrum to the inner ear. The sound-receiving organ is the cochlea, which is located in the inner ear.

The snail is a small tube twisted in a spiral in the form of two and a half special turns. It is filled with a viscous liquid. When sound vibrations enter the inner ear, they are transmitted to the fluid, which sways and acts on the sensitive hairs. Information in the form of impulses is sent to the brain, analyzed, and we hear sounds.

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The eye is the human organ of vision. This complex structure is located in the orbital sockets of the skull.

There are several accessory organs around the eyes, including the eyelids, eyebrows and eyelashes, the external eye muscles and the lacrimal apparatus. The eyelids protect the eye from foreign bodies and strong light, and during sleep they moisturize the eyeball, covering its surface with liquid. The lacrimal apparatus is a collective term for several organs involved in the production of the fluid we call tears. This liquid is a mixture of mucus, aqueous solution salt and an enzyme that cleanses and lubricates the eyeball.

Among the external eye muscles These include six muscles that allow the eyeball to move. Each of them is responsible for moving the eye in a certain direction. These movements are controlled by three cranial nerves that connect the eye to the brain stem and cerebellum.

The eyeball is located in the orbital socket of the skull - only the front part of the eye is outside. It is covered with a strong protective white membrane, the sclera, which makes up the white of the eye and gives the eye its shape. The anterior surface of the eye is covered transparent cornea, through which you can see the iris and pupil. The middle layer of the eye is the choroid, which includes the choroid itself, the ciliary body and the iris.

The choroid contains a large number of blood vessels. It passes through the sclera and back wall eyes, supplying the retina nutrients. The ciliary body, located at the front of the eye, consists of ciliary processes that secrete aqueous fluid and the ciliary muscle, which changes the shape of the lens to focus it on near or distant objects.

The iris, consisting of muscle fibers, determines eye color. It is connected to the ciliary processes and is located between the lens and the cornea. The main function of the iris is to regulate the amount of light entering the eye through the pupil, which is a hole in the center of the eye. For example, when a direct line hits the eye sunlight, the orbicularis muscles of the iris contract, reducing the size of the pupil, and therefore the amount of light passing through it. In low light, the radial muscles contract, causing the pupil to dilate and increase the amount of light passing through it.

The inner layer of the eye is the retina, a light-sensitive structure made of nerve tissue and pigment cells. Pigment cells absorb scattered radiation, providing clarity and sharpness of the image transmitted by light. Nervous tissue contains neurons that process visual images and transmit them to the brain. These neurons are arranged in three layers. The photoreceptor layer consists of rods and cones. Rods perceive black-and-white visual information in dim light, and cones perceive color information in bright light.

Disc located on the anterior surface of the retina optic nerve, in this place the optic nerve and blood vessels the retinas are connected to the eyeball. The optic disc is located on top of the layer nerve cell, it is called a blind spot in the retina because it does not perceive visual information.

The lens of the eye - focuses light rays. It is located behind the iris and pupil. Under the influence of the ciliary muscle, the lens can change shape and focus on near or distant objects, accordingly refracting the rays passing through it. The lens divides inner area the eyeball into two parts: the anterior and posterior chambers. The anterior chamber consists of watery liquid, thanks to which the eye retains its shape, in addition, this liquid contains substances that nourish the cornea and lens. The rear chamber is filled with jelly-like vitreous, which maintains the shape of the eyeball and holds the retina in place, pressing it against the choroid.

Hearing and balance.

The ear is an organ that perceives sound signals and allows us to maintain balance.

It consists of three sections: the outer, middle and inner ear. The outer ear includes three parts: the pinna, the external auditory canal and the eardrum. Auricle- a protruding part of the body that consists of elastic cartilage covered with skin. The external auditory canal is a tube approximately 2.5 cm long that leads to the eardrum, which separates the outer ear from the middle ear. Inner surface This canal at the entrance is covered with hairs, in addition, there are sebaceous glands. These glands produce a substance commonly called sulfur. Together with the hairs, it protects the ear from dust.

The eardrum is transparent in places and consists of several types. When sound waves reach the membrane, it vibrates, these vibrations are transmitted to the middle ear.

Middle ear, or tympanic cavity, located in temporal bone and covered with mucous membrane. It contains the following elements hearing aid, such as the Eustachian tubes, ossicles, oval window and cochlear window. Eustachian tube connects the bottom of the middle ear with the nasopharynx. When swallowing and yawning, this channel opens, so the air pressure on both sides of the eardrum is equalized, and it responds better to sound waves. The bones (hammer, incus and stapes) run along the entire length of the middle ear and are attached to its walls by ligaments. They got their name because of their characteristic shape.

The bones are connected to each other by joints, and the malleus is also connected to the eardrum. The vibrations of the membrane are transmitted to the bones - first to the malleus, then to the incus and, finally, to the stapes connected to the membrane oval window. The fenestra cochlea is located directly below the oval window and is covered by the secondary tympanic membrane. Both windows open into the inner ear.

This part of the ear is also called the labyrinth, it consists of the cochlea and the semicircular canal. The cochlea is a bony tube in the form of a spiral of three channels, which are separated by two types of septum.

The hearing organ is located on one of these partitions, it consists of cells and neurons auditory nerve. Sound vibrations from the oval window are transmitted to the cochlea in the form of pressure waves. Complex reactions occur in the cochlea that transmit sound to the brain using nerve impulses.

The semicircular canals contain balance receptors. These channels are located at right angles to each other and expand at one end to form three vesicles containing sensory cells. Some of these cells are connected to nerve fibers. In response to head movements, fluid in the semicircular canals moves and sensory cells send impulses to the brain. Equilibrium is maintained by the relative position of the semicircular canals and the different speeds of fluid movement in them.

Taste.

We taste various substances after they are split into individual chemical substances. Taste buds contain taste receptors and are located on the tongue and soft palate of the mouth, as well as in the pharynx and larynx.

Groups of sensory cells on the tongue are organized into oval bodies called taste buds. The kidneys are located in the walls of the papillae - tubercles on the mucous membrane covering the tongue. There are three types of papillae - mushroom-shaped and groove-shaped (most of the taste buds are located on them), as well as leaf-shaped, giving tactile sensations. The circumvallate papillae are the largest. They are located at the base of the tongue, and mushroom-shaped - along its entire surface.

Nerve endings, that is, sensory cells of the taste buds, perceive taste only if the substance has been previously dissolved in saliva. Our body perceives four tastes: sour, salty, bitter and sweet. The various sensations that give us different kinds food are a combination of these primary taste sensations and olfactory stimuli.

The surface of the tongue can be divided into “taste zones,” each of which responds particularly strongly to one of the primary tastes. The tip of the tongue is sensitive to sweet and salty, the base - to bitter, and side surfaces- react to sour things.

From nerve fibers in the kidneys, taste impulses are transmitted along cranial nerves in various areas of the brain in which the taste of food is determined.

Smell.

The perception of odors, or smell, has chemical nature: We perceive odors through the interaction of molecules with receptor cells located in the upper part of the nasal cavity. Olfactory receptors are neurons. The lifespan of which is about a month.

At the ends of these neurons there are olfactory hairs that act as conductors of nerve impulses. Located in connective tissue The gland produces mucus, which flows through ducts to the surface of the olfactory epithelium, dissolving molecules of odorous substances. Olfactory receptors become nerves that carry impulses to the olfactory bulbs in the brain.

The human sense of smell is rather poorly developed compared to the sense of smell in animals. Olfactory impulses are transmitted to the departments forebrain, responsible for emotions, so certain smells can evoke certain memories and reactions in us.

Touch.

Skin receptors perceive two types of tactile sensations: direct tactile (touch, pressure and vibration) and thermal (temperature changes).

Touch sensations are stimulated by receptors, nerve endings on the skin or tissues. Around the end nerve fiber There are oval-shaped Meissner corpuscles consisting of connective tissue. They are receptors that instantly transmit impulses along the nerves. Especially a lot of them in the fingertips, on the palms and feet.

Pressure is perceived by receptors located in deeper layers of tissue.