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Hearing and balance analyzers
The human world is filled with sounds. Listening and perceiving sounds, a person learns about what is happening around him, communicates with people, feels danger, evaluates distances, enjoys music. A person also constantly feels his position in space.
STRUCTURE OF THE ORGANS OF HEARING. Sound is vibrations in the air. Our hearing organ picks up vibrations with a frequency of 16-20 thousand per second. The path that sound travels in the ear is much more complicated than the path of a beam of light in the eye.
The organ of hearing is divided into the outer, middle and inner ear.
outer ear includes auricle and external auditory canal. The auricle is adapted to capture sounds; in humans, it is motionless. The ear canal connects the auricle to the middle ear. The outer ear is separated from the middle eardrum, which converts sound waves into mechanical vibrations and transmits them to the middle ear.
Middle ear is located in the thickness of the temporal bone and is a narrow cavity (1-2 cm 3), in which three auditory ossicles are located. The middle ear cavity (tympanic cavity) continues into auditory tube, which opens into the throat. This allows you to equalize the pressure in the middle ear cavity with atmospheric pressure, so that the eardrum does not distort sound vibrations.
auditory ossicles - hammer, anvil and stapes- the smallest bones of our body, their weight is only about 0.5 g. They form a system of levers that amplifies the weak vibrations of the eardrum 50 times and transmits them to the inner ear.
Position of sensitive cells and integumentary membrane
Organ of Corti
hair cells
Sound perception
inner ear is a complex system of thin curved canals and cavities located in the thickness of the temporal bones. Inside this bony labyrinth is a membranous labyrinth that repeats the shape of the bone labyrinth. All cavities of the labyrinth are filled with liquid. There are two organs in the labyrinth at once: the organ of hearing and the organ of balance - the vestibular apparatus. Hearing function is performed snail- spirally curled part of the labyrinth. The other part of it is bony vestibule and three semicircular canals- responsible for balance, determines the position of the body in space.
The cochlea is a spirally twisted bone canal 3.5 cm long, forming 2.5 turns. Two membranes running along the entire cochlea divide its cavity into three parallel canals. The lower membrane is called the main, on it is the organ of Corti - receptor cells with numerous sensitive hairs. The hairs protrude into the middle canal of the cochlea, filled with fluid - endolymph. Above them, in the form of a cornice, hangs the second membrane running along the cochlea - the integumentary. In the other two canals of the cochlea (upper and lower) there is perilymph - a liquid similar in composition to lymph and blood plasma.
WORK OF THE ORGAN OF HEARING. Let's look at how the auditory analyzer works. The auricles pick up sound vibrations and direct them to the ear canal. Through it, vibrations are sent to the middle ear and, reaching the eardrum, cause its vibrations. Through the system of auditory ossicles, vibrations are transmitted further - to the inner ear. In the plate separating the cavities of the middle and inner ear, there are two "windows" covered with thin membranes. In one of them - oval - rests the stirrup, transmitting sound vibrations to the membrane.
Its vibrations cause the movement of fluid in the cochlea, which, in turn, causes the basement membrane to vibrate. When the fibers move, the hairs of the receptor cells touch the integumentary membrane. Excitation occurs in the receptors, which is ultimately transmitted through the auditory nerve to the brain, where, through the midbrain and diencephalon, excitation enters the auditory zone of the cerebral cortex, located in the temporal lobes. Here is the final distinction of the nature of the sound, its tone, rhythm, strength, pitch, and, finally, its meaning.
BALANCE BODY. Most animals have special balance organs. They can be simple, like some crayfish. This function is performed by the otolithic organ; the grains of sand in it irritate sensitive cells, and thanks to this, the cancer senses the position of its body in space.
In humans, the function of the organ of balance (it is also called vestibular apparatus) performs part of the inner ear - these are two small sacs (vestibule) and three semicircular canals. The channels are annularly curved tubes lying in three mutually perpendicular planes. The cavities of the vestibule and semicircular canals are filled with fluid.
Receptors are located in the walls of the cavities of the semicircular canals, their structure is similar to the sensitive hair receptors of the organ of hearing. In the walls of the sacs of the vestibule are small crystals of calcium carbonate.
Balance organ
At the end of each semicircular canal there is an extension (ampulla) in which there is an ampulla scallop - an outgrowth, which includes sensitive hair cells.
The mechanism of the vestibular apparatus is quite simple. When a person's head is in a vertical position, the crystals located in the zone of the vestibule receptors of the inner ear put pressure on the hairs of sensitive cells in a certain way. When the head is turned to the right or to the left, the ampullar scallops in the semicircular canals are displaced, and the pressure on the sensitive cells changes accordingly - either on the right side, or on the left.
The pressure of the crystals and the inclination of the scallops cause excitation of the receptors. The resulting nerve impulses are conducted to the brain (midbrain, cerebellum, cerebral cortex). From the brain, response impulses are sent to various groups of skeletal muscles. Their reflex contraction takes place, and the balance of the body, if it has been disturbed, is restored.
The vestibular apparatus constantly informs the central nervous system about the position of the body (head) in space.
The energy level of sound vibrations is measured in decibels (dB). Strictly speaking, this is the volume of the sound. The whisper of a person is estimated at approximately 15 dB, and the rustle of leaves falling from a tree is estimated at 10 dB. A conversation between two people is conducted at a level of 60 dB, but the noise of heavy traffic reaches 90 dB. Noise above 100 dB is almost unbearable for a person. Sound above 140 dB is dangerous to the human ear and can damage the eardrum. The noise emitted by a rock band during a concert is about 110 dB and can cause pain for many people. Prolonged strong sound exposure leads to an inevitable decrease in hearing acuity. Particularly dangerous are periodic amplifications of the sound volume. No wonder the riveters working with pneumatic hammers were called "grouse". Noise of 200 dB can kill a person very quickly.
The embryo senses sound vibrations even in the womb. The future person perfectly remembers the sounds of the mother's heartbeat and rejoices when he hears their recording after birth. This is used for practical purposes: the mother's heartbeat, recorded on an audio medium, is given to listen to the baby so that he calms down and falls asleep.
The most primitive vertebrates, the lampreys, have only two semicircular canals. Perhaps their ancestors lived at the very bottom of the sea and moved only in one plane: left - right, forward - back, but up and down they never moved. That is why, living in "two-dimensional space", the lamprey ancestors did very well without the third semicircular canal, which appeared in the process of evolution in real fish living in a three-dimensional world.
Like any other analyzer, the vestibular one needs training. So, astronauts train for a long time in order to be able to work in zero gravity. People can get sick, and not only in the sea during its excitement, but also in transport. During pumping, the fluid in the semicircular canals constantly moves and excites the receptors, and the brain centers of most people react to this with unpleasant sensations.
Test your knowledge
1. List the three parts of the auditory analyzer.
2. Make a table "The structure and work of the ear", indicating for each department its parts and transformations that occur with sound.
3. Recall from the zoology course how the hearing organ in frogs was represented; lizards; birds.
4. Why did the muscles that move the auricles lose their original meaning in humans?
5. Where is the tympanic membrane located, what is its significance? Why do artillerymen cover their ears and open their mouths when firing their guns?
6. How is the distinction of sound in pitch?
7. Think about the function of the round window.
8. What structures of the inner ear convert fluid vibrations into nerve impulses?
9. What is ultrasound for a person; infrasound?
10. Where is the organ of balance located? How is it arranged?
Work with computer
http://school-collection.edu.ru/catalog (Anatomical and physiological atlas of a human / Analyzers and sense organs / Organ of hearing. Organ of balance)
The organ of hearing consists of the outer, middle and inner ear. The outer ear picks up sound vibrations and sends them to the middle ear. The ossicular system transmits sound vibrations further to the inner ear. Vibrations of fluid in the cochlea cause oscillations of the basement membrane and touching of the hair cells of the integumentary membrane, which leads to irritation of the receptors in contact with it.
The resulting excitation is transmitted to the auditory zone of the cerebral hemispheres, where sound is distinguished.
Part of the inner ear - the vestibular apparatus performs the function of an organ of balance.
Skin and muscle sensitivity. Smell. Taste
MUSCLE FEELING. Close your eyes, focus. Now describe the state of your body. Yes, you feel that you are standing or lying, your arm or leg is extended or bent. With your eyes closed, you can touch any part of your body with your hand. The thing is that from the receptors of muscles, tendons, joint capsules, ligaments, there are constantly impulses that inform the brain about the state of the organs of the musculoskeletal system. When muscles contract or stretch, excitation occurs in special receptors, which through the middle and intermediate sections of the brain enters the motor zone of the cerebral cortex, namely, into the anterior central gyrus of the frontal lobe. Motor Analyzer- the oldest of the analyzers, since nerve and muscle cells developed in animals almost simultaneously.
TACTILE ANALYZER. Touch- this is a complex of sensations that occur when the skin receptors are irritated. Touch receptors (tactile) are of two types: some of them are very sensitive and are excited when the skin on the hand is indented by only 0.1 microns, others only with significant pressure. On average, 1 cm 2 accounts for about 25 tactile receptors. They are scattered throughout the body very unevenly: for example, in the skin covering the lower leg, there are about 10 receptors per 1 cm 2, and about 120 such receptors on the same area of the skin of the thumb. There are a lot of touch receptors on the tongue and palms. In addition, the hairs that cover 95% of our body are sensitive to touch. At the base of each hair is a tactile receptor. Information from all these receptors is collected in the spinal cord and, along the conducting paths of the white matter, enters the nuclei of the thalamus, and from there - to the highest center of tactile sensitivity - the region of the posterior central gyrus of the cerebral cortex.
Pressure receptors and receptors located in muscles and tendons help us navigate in space
Skin receptors and related sensations
In addition to touch receptors, there are receptors in the skin that are sensitive to cold and heat. Cold receptors about 250 thousand on the human body, thermal much less - about 30 thousand. These receptors are selective: they are able to distinguish only the signal to which they are tuned, that is, either heat or cold. Like other sensations, the sense of touch is not immediately formed in a person. The infant feels the touch of a hot or sharp object from the first days of life, but, apparently, this is a pain sensation. But on a weak touch to the skin, he begins to react only after a few weeks.
OLFACTORY ANALYZER. The sense of smell provides the perception of smells. Olfactory receptor cells are located in the mucous membrane of the upper part of the nasal cavity. There are about 100 million of them. Each of these cells has many short olfactory hairs, that enter the nasal cavity. It is with the surface of these hairs that the molecules of odorous substances interact. The total area occupied by olfactory receptors in humans is 3–5 cm 2 (for comparison: in a dog - about 65 cm 2, in a shark - 130 cm 2). The sensitivity of the olfactory hairs in humans is not very high. It is believed that a dog's sense of smell is about 15 to 20 times sharper than a human's.
The signal from the hairs passes to the body of the olfactory cell and further to the human brain. The path of information about odors to the brain is very short. Impulses from the olfactory epithelium arrive, bypassing the midbrain and diencephalon, directly to the inner surface of the temporal lobes, where a sense of smell is formed in the olfactory zone. And although by the standards of the animal world, a person’s sense of smell is unimportant, we are able to distinguish at least 4 thousand different smells, and according to the latest information, up to 10 thousand. Currently, there are six main smells that make up all the rest: floral , fruity, fetid, spicy, resinous, burning smell. To form an odor, the smallest particles of a substance - molecules must enter the nasal cavity and interact with the receptor on the hair of the olfactory cell. More recently, it was found that these cells differ, as they are initially tuned to a certain smell and are able to recognize different odorous molecules.
Transmission of olfactory and gustatory stimuli to the brain
Olfactory organ
TASTE ANALYZER. The peripheral part of the taste analyzer is taste receptor cells. Most of them are located in the epithelium of the tongue. In addition, taste buds are located on the back of the pharynx, soft palate and epiglottis. Receptor cells are grouped together taste buds, which are collected in three types of papillae: mushroom-shaped, trough-shaped and foliate.
The taste bud is bulb-shaped and consists of supporting and receptor cells. The kidneys do not reach the surface of the mucous membrane, they are buried and connected with the oral cavity by a small channel - the taste pore. Directly below the pore is a small chamber into which microvilli of receptor cells protrude. Taste buds react only to substances dissolved in water; insoluble substances have no taste. A person distinguishes four types of taste sensations: salty, sour, bitter, sweet. Most of the receptors susceptible to sour and salty taste, located on the sides of the tongue sweet- at the tip of the tongue bitter- at the root of the tongue. Each receptor cell is most sensitive to a particular taste.
organ of taste
Tongue surface
Taste zones of the tongue
When food enters the mouth, it dissolves in saliva, and this solution enters the cavity of the chamber, acting on the receptors. If a receptor cell reacts to a given substance, it becomes excited. From receptors information about taste stimuli in the form of nerve impulses along the fibers glossopharyngeal and partially facial and vagus nerve enters the midbrain, the nuclei of the thalamus and, finally, on the inner surface of the temporal lobes of the cerebral cortex, where the higher centers of the taste analyzer are located.
In determining taste, in addition to taste sensations, olfactory, temperature, tactile, and sometimes even pain receptors (if a caustic substance gets into the mouth) are involved. The combination of all these sensations determines the taste of food.
Next to the taste buds are glands that secrete a fluid that constantly bathes the papillae. Therefore, taste sensations do not last long, and soon a person is able to perceive new sensations.
fungiform papilla
foliate papilla
Gutter papilla
Part of the nerve impulses from the olfactory epithelium does not go to the temporal lobes of the cortex, but to the tonsils - nuclei located deep in the temporal lobes and which are part of the limbic system. These structures also contain centers of anxiety and fear. Such substances have been found, the smell of which can cause horror in people, while the smell of lavender, on the contrary, calms, making people more good-natured for a while. In general, any unfamiliar smell should cause unconscious anxiety, because for our distant ancestors it could be the smell of a human enemy or a predatory animal. So we inherited such an ability to react to smells with emotions. Smells are perfectly remembered and are able to awaken the emotions of long forgotten days, both pleasant and unpleasant.
Signs that the baby is able to distinguish the smell begin to appear by the end of the first month of life, but the baby does not show any preference for certain aromas at first.
Taste sensations are formed in a person before all others. Even a newborn baby is able to distinguish mother's milk from water.
Taste buds are the shortest-lived sensory cells in the body. The life span of each of them is about 10 days. After the death of the receptor cell, a new receptor is formed from the basal cell of the kidney. An adult has 9-10 thousand taste buds. Some of them die off with age.
Pain is an unpleasant sensation that indicates damage to the body or the threat of it due to injury or illness. Pain is perceived by the branched endings of special nerves. There are at least a million such endings in human skin. In addition, an extremely strong effect on any receptor (visual, auditory, tactile, etc.) leads to the formation of pain in the brain. The highest pain center is located in the thalamus, and it is there that the sensation of pain is formed. If you hit your finger with a hammer, then the signal from pain endings and other receptors will go to the nuclei of the thalamus, pain will arise in them and will be projected to the place where the hammer hit. The formation of pain sensations very much depends on the emotional state and level of intelligence of a person. For example, elderly and middle-aged people tolerate pain more easily than young people, and even more so children. Intelligent people are always more restrained in the outward manifestation of pain. People of different races and peoples have different attitudes towards suffering. Thus, the inhabitants of the Mediterranean react to pain effects much stronger than the Germans or the Dutch.
It is hardly possible to assess the strength of pain objectively: the sensitivity to pain in different people is very different. It can be high, low, or even completely absent. Contrary to popular belief, men are much more patient than women. The increased pain sensitivity of women is determined by the hormones that their body produces. But during pregnancy, especially at its end, pain sensitivity is significantly reduced so that the woman suffers less during childbirth.
Currently, in the arsenal of physicians there are very good long-acting painkillers - analgesics. Local analgesics should be administered where pain occurs, for example, in the area of a tooth being removed. Such drugs block the conduction of impulses along the pain pathways to the brain, but they do not last very long. For general anesthesia, you have to immerse a person in an unconscious state with the help of special substances. The best pain blockers are substances similar to morphine. But, unfortunately, their use cannot be wide, since they all lead to drug addiction.
Test your knowledge
1. What is muscle feeling? Why is the motor analyzer the oldest of the analyzers?
2. Why can't a person move with his eyes closed if his muscular sense is disturbed?
3. What information do we receive with the help of touch? What part of the body has the most tactile receptors?
4. Why does a person feel an object with his hands in order to better study it?
5. In what state should a substance be in order for a person to feel its taste; smell?
6. Where is the olfactory organ located? How does the sense of smell come about?
7. What are the functions of the organ of taste? How does the sensation of taste arise?
8. Where are taste buds located? Why, touching food with only the tip of the tongue, it is impossible to determine its taste?
9. Why does food seem tasteless during a bad cold?
Work with computer
Refer to the electronic application. Study the material of the lesson and complete the suggested tasks.
http://school-collection.edu.ru/catalog (Human Anatomical and Physiological Atlas / Analyzers and Sense Organs / Tongue. Taste receptors; Nose. Olfactory receptors; Skin receptors)
With the help of muscle feeling, a person feels the position of parts of his body in space. The taste analyzer protects a person from the presence of harmful substances in food. The olfactory analyzer takes part in determining the quality of food, water, air.
Muscular feeling. Close your eyes, focus. Now describe the state of your body. Yes, you feel that you are standing or lying, your arm or leg is extended or bent. With your eyes closed, you can touch any part of your body with your hand. The thing is that from the receptors of muscles, tendons, joint capsules, ligaments, there are constantly impulses that inform the brain about the state of the organs of the musculoskeletal system. When muscles contract or stretch, excitation occurs in special receptors, which through the middle and intermediate sections of the brain enters the motor zone of the cerebral cortex, namely, into the anterior central gyrus of the frontal lobe. The motor analyzer is the oldest of the sense organs, since nerve and muscle cells developed in animals almost simultaneously.
Tactile analyzer. Touch is a complex of sensations arising from irritation of skin receptors. Touch receptors (tactile) are of two types: some of them are very sensitive and are excited by indentation of the skin on the hand by only 0.1 microns, others - only with significant pressure. On average, there are about 25 tactile receptors per 1 cm2. They are scattered throughout the body very unevenly: for example, in the skin covering the lower leg, there are about 10 receptors per 1 cm 2, and about 120 such receptors on the same area of the skin of the thumb. There are a lot of touch receptors on the tongue and palms. In addition, the hairs that cover 95% of our body are sensitive to touch. At the base of each hair is a tactile receptor. Information from all these receptors is collected in the spinal cord and, along the white matter pathways, enters the nuclei of the thalamus, and from there - to the highest center of tactile sensitivity - the area of \u200b\u200bthe posterior central gyrus of the cerebral cortex.
In addition to touch receptors, there are receptors in the skin that are sensitive to cold and heat. There are about 250 thousand cold receptors on the human body, much less thermal ones - about 30 thousand. These receptors are selective: they are able to distinguish only the signal to which they are tuned, that is, either heat or cold. Like other sensations, the sense of touch is not immediately formed in a person. The infant feels the touch of a hot or sharp object from the first days of life, but, apparently, this is a pain sensation. But on a weak touch to the skin, he begins to react only after a few weeks.
Olfactory analyzer. The sense of smell provides the perception of smells. Olfactory receptor cells are located in the mucous membrane of the upper part of the nasal cavity. There are about 100 million of them. Each of these cells has many short olfactory hairs that extend into the nasal cavity. It is with the surface of these hairs that the molecules of odorous substances interact. The total area occupied by olfactory receptors in humans is 3-5 cm 2 (for comparison: in a dog - about 65 cm 2, in a shark - 130 cm 2). The sensitivity of the olfactory hairs in humans is not very high. It is believed that a dog's sense of smell is approximately 15-20 times sharper than a human's.
The signal from the hairs passes to the body of the olfactory cell and further to the human brain. The path of information about odors to the brain is very short. Impulses from the olfactory epithelium arrive, bypassing the midbrain and diencephalon, directly to the inner surface of the temporal lobes, where a sense of smell is formed in the olfactory zone. And although by the standards of the animal world, a person’s sense of smell is unimportant, we are able to distinguish at least 4 thousand different odors, and according to the latest information, up to 10 thousand. Currently, there are six main odors that make up all the rest: floral , fruity, fetid, spicy, resinous, burning smell. To form an odor, the smallest particles of a substance - molecules must enter the nasal cavity and interact with a receptor on the hair of the olfactory cell. More recently, it was found that these cells differ, as they are initially tuned to a certain smell and are able to recognize different odorous molecules.
Taste analyzer. The peripheral part of the taste analyzer is taste receptor cells. Most of them are located in the epithelium of the tongue. In addition, taste buds are located on the back of the pharynx, soft palate and epiglottis. Receptor cells are combined into taste buds, which are collected in three types of papillae - mushroom-shaped, trough-shaped and leaf-shaped.
The taste bud is bulb-shaped and consists of supporting, receptor and basal cells. The kidneys do not reach the surface of the mucous membrane, they are buried and connected with the oral cavity by a small channel - the taste pore. Directly below the pore is a small chamber into which microvilli of receptor cells protrude. Taste buds react only to substances dissolved in water; insoluble substances have no taste. A person distinguishes four types of taste sensations: salty, sour, bitter, sweet. Most of the receptors susceptible to sour and salty tastes are located on the sides of the tongue, to sweet - on the tip of the tongue, to bitter - on the root of the tongue. Each receptor cell is most sensitive to a particular taste.
The receptors that capture dissolved chemicals are called taste buds. They are small tubercles on which special taste-perceiving cells are located. There are about 50 such cells in one papilla. In appearance, the papillae that perceive various taste sensations do not differ, however, special receptor substances are produced in them, some of which react, for example, to bitter, others to sweet, etc.
When food enters the mouth, it dissolves in saliva, and this solution enters the cavity of the chamber, acting on the receptors. If a receptor cell reacts to a given substance, it becomes excited. From the receptors, information about taste stimuli in the form of nerve impulses along the fibers of the glossopharyngeal and partially facial and vagus nerves enters the midbrain, thalamic nuclei and, finally, to the inner surface of the temporal lobes of the cerebral cortex, where the higher centers of the taste analyzer are located.
In determining taste, in addition to taste sensations, olfactory, temperature, tactile, and sometimes even pain receptors (if a caustic substance gets into the mouth) are involved. The combination of all these sensations determines the taste of food.
- Part of the nerve impulses from the olfactory epithelium does not enter the temporal lobes of the cortex, but into the amygdala complex of the limbic system. These structures also contain centers of anxiety and fear. Such substances have been found, the smell of which can cause horror in people, while the smell of lavender, on the contrary, calms, making people more good-natured for a while. In general, any unfamiliar smell should cause unconscious anxiety, because for our distant ancestors it could be the smell of a human enemy or a predatory animal. So we inherited such an ability - to react to smells with emotions. Smells are perfectly remembered and are able to awaken the emotions of long forgotten days, both pleasant and unpleasant.
- Signs that the baby is able to distinguish the smell begin to appear towards the end of the first month of life, but the baby does not show any preference for certain aromas at first.
- Taste sensations are formed in a person before all others. Even a newborn baby is able to distinguish mother's milk from water.
- Taste buds are the shortest-lived sensory cells in the body. The life span of each of them is about 10 days. After the death of the receptor cell, a new receptor is formed from the basal cell of the kidney. An adult has 9-10 thousand taste buds. Some of them die off with age.
- Pain is an unpleasant sensation that indicates damage to the body or the threat of it due to injury or illness. Pain is perceived by the branched endings of special nerves. There are at least a million such endings in human skin. In addition, an extremely strong effect on any receptor (visual, auditory, tactile, and others) leads to the formation of pain in the brain. The highest pain center is located in the thalamus, and it is there that the sensation of pain is formed. If you hit your finger with a hammer, then the signal from pain endings and other receptors will go to the nuclei of the thalamus, pain will arise in them and will be projected to the place where the hammer hit. The formation of pain sensations very much depends on the emotional state and level of intelligence of a person. For example, elderly and middle-aged people tolerate pain more easily than young people, and even more so children. Intelligent people are always more restrained in the outward manifestation of pain. People of different races and peoples have different attitudes towards suffering. Thus, the inhabitants of the Mediterranean react to pain effects much stronger than the Germans or the Dutch.
It is hardly possible to assess the strength of pain objectively: the sensitivity to pain in different people is very different. It can be high, low, or even completely absent. Contrary to the prevailing opinion, men are much more patient than women, and strong pain sensations occur in representatives of different sexes in different organs. The increased pain sensitivity of women is determined by the hormones that their body produces. But during pregnancy, especially at its end, pain sensitivity is significantly reduced so that the woman suffers less during childbirth.
- Currently, in the arsenal of physicians there are very good long-acting painkillers - analgesics. Local analgesics should be administered where pain occurs, for example, in the area of a tooth being removed. Such drugs block the conduction of impulses along the pain pathways to the brain, but they do not last very long. For general anesthesia, you have to immerse a person in an unconscious state with the help of special substances. The best pain blockers are substances similar to morphine. But, unfortunately, their use cannot be wide, since they all lead to drug addiction.
Test your knowledge
- What is muscle feeling?
- What receptors provide skin sensitivity?
- What information do we receive with the help of touch?
- What part of the body has the most tactile receptors?
- In what state must a substance be in order for a person to feel its taste, smell?
- Where is the olfactory organ located?
- How does the sense of smell come about?
- What are the functions of the organ of taste?
- How does the sensation of taste arise?
Think
- Why is a person unable to move with his eyes closed if the muscular sense is disturbed?
- Why does a person touch an object in order to study it better?
With the help of muscle feeling, a person feels the position of parts of his body in space. The taste analyzer protects a person from the presence of harmful substances in food. The olfactory analyzer takes part in determining the quality of food, water, air.
Few of us think about muscle feeling and give it exceptional importance. Meanwhile, thanks to him, even closing his eyes, a person unmistakably feels in what position in spatial relation his arm is - whether it is bent or raised up, in what position his body is - he is sitting or standing. Such regulation of movements is determined by the work of special proprioceptors located in the muscles, articular bags, ligaments, and in the skin. Let's take a closer look at what muscle feeling is.
A special form of knowledge
The complex of sensations that arise due to the functioning of the body is called a muscular feeling. This concept was introduced into use by I. M. Sechenov. The scientist argued that, for example, when a person walks, not only his sensations from the contact of the leg with the surface are important, but also the so-called muscle sensations that accompany the contraction of the corresponding organs.
The interpretation of the question of what a muscular feeling is, was given by I. M. Sechenov as a special form of man's knowledge of the spatio-temporal relations of his environment.
Muscular feeling, the scientist gave a special purpose in the regulation of movements. He assigned vision and vision the role of the closest regulators, thanks to which a person is able to compare objects, perform simple operations of analysis and synthesis.
"Dark" feeling
Muscular was called "dark" and for a rather long period they did not separate from touch, calling both concepts haptics. Thus, the psychologist William James emphasized the extreme uncertainty of this concept. Because it is not clear what we are talking about - about residual sensations from a posture or movement, or some kind of efferent impulses sent by the brain.
Indeed, in most cases, a person is not aware of the work of muscles, but only movement. The sensations experienced when moving, maintaining a certain posture, straining the vocal cords or gesticulating, are almost not realized.
Kinesthesia
At the turn of the 19th and 20th centuries, the question of what muscle feeling is and how to determine it was still on the agenda. The neurologist Henry-Charlton Bastian began to express this concept, or, as he wrote, “feelings of movement”, with the word “kinesthesia”.
Kinaesthesia was understood as the ability of the brain to be continuously aware of the movement and position of the muscles of the body and its various parts. This ability was achieved thanks to proprioceptors, which send impulses to the brain from the joints, tendons, and muscles.
The term entered the scientific language quite firmly and even gave rise to several derivative concepts, such as kinesthetic empathy, kinesthetic pleasure, kinesthetic imagination, which is understood as liberation from the usual and normative ways of moving and the ability to create new motor “events”.
Proprioreceptors
How to understand what a muscle feeling is?
Awareness of the position and movement of the muscles of the body and its various parts is associated with the work of special proprioceptors - nerve endings located in the muscular-articular apparatus. Their excitation during muscle stretching or contraction is sent by impulses to receptors along nerve fibers in the central nervous system. This allows a person, without controlling his movements with his eyesight, to change the position of the body or posture, makes it possible to touch the tip of the nose with the exact movement of a finger.
Such signals are very important for the orientation of the body in space. Without them, a person would not be able to perform any coordinated movement. Muscular feeling in the work of people in such professions as a surgeon, driver, violinist, pianist, draftsman, turner and many others plays an important role. Special regulating impulses enable them to make subtle and precise movements.
A person, being conscious, constantly feels the passive or active position of his body parts and the movement of the joints. They accurately determine the resistance to each of their movements. Such abilities taken together are called proprioception, since the stimulation of the corresponding proprioceptors (receptors) does not come from the external environment, but from the body itself. Often they are called deep sensitivity. This is due to the fact that most of the receptors are located in extracutaneous structures: in muscles, joints and their capsules, tendons, ligaments, periosteum, fascia.
Muscular-articular feeling, thanks to proprioceptors, allows a person to have a sense of the position of his body in space, as well as a sense of strength and movement. The first one is practically not subject to adaptation and carries information about the angle at which a certain joint is currently located, and, accordingly, about the position of all limbs. The sense of movement allows you to realize the direction and speed of movement of the joints. At the same time, a person with muscle contraction equally perceives active and passive action. The threshold for perception of movements depends on their amplitude and on the rate of changes in the angle of joint flexion.
The sense of strength allows you to assess the muscle strength that is necessary for movement or to keep the joints in a certain position.
The meaning of muscle feeling
For a person, musculoskeletal feeling is of no small importance. It allows you to correctly find objects and determine the position of the body in space with your eyes closed. Muscular feeling helps to determine the mass and volume of objects, to make a fine analysis of movements, their coordination. Its value especially increases with a fall in vision or its loss.
dysfunction of the motor analyzer leads to the fact that a person loses the accuracy of movements. His gait becomes unsteady and unsteady, he loses his balance. In people with similar disorders, vision takes over the function of the so-called nearest regulator.Muscular feeling in a state of weightlessness
Muscular feeling in a person in space flights is absent. In the state of weightlessness, in which there is no support force, the orientation of spatial relationships is perceived through visual perception and visual evaluation.
The experience of orbital flights and access to unsupported space by cosmonauts showed that a person is able to adapt to conditions so unusual for him. There are other relationships between him. Tactile, muscular-articular sensations, vision acquire the main importance, a slightly smaller influence is attributed to signaling from the otolithic device. Such analyzers are unstable.
In future flights of cosmonauts and their further separation in unsupported space, the possibility of the appearance of disorientation and spatial illusions is not ruled out. That is why the problem of human orientation in outer space is quite relevant.
musculo-articular reception, proprioception, the ability of humans and animals to perceive and evaluate changes in the relative position of body parts and their movement. The role of information about the position of one or another part of the body in space and about the degree of contraction of each of the muscles in the regulation of movements and cognition of the environment was first pointed out by I. M. Sechenov, who called mechanism "dark muscle feeling." Nerve impulses that arise in muscle-articular (kinesthetic) receptors - proprioreceptors (See Proprioreceptors) (these include muscle spindles, Golgi bodies, and possibly Pacini bodies) during muscle contraction and stretching reach the central nervous system through sensitive nerve fibers. The totality of the peripheral and central nervous formations participating in the analysis of this information is called by IP Pavlov the motor analyzer (See Motor analyzer). The perfection and subtlety of the coordination of motor reactions, including locomotion (see Locomotion), carried out by animals and humans, are explained by the accumulation during the life of the organism of ever new connections between the neurons of the motor analyzer and other analyzers (see Analyzers) (visual, auditory, and etc.). M. h. plays an important role in the development of the body's perceptions, since it serves as the main control of the remaining sense organs. So, a visual assessment of the distance of an object is developed with the help of the M. h. when approaching the object.
O. M. Benyumov.
- - a complex of sensations that arise due to the work of the muscular system of the body ...
Great Psychological Encyclopedia
- - a complex receptor organ in the skeletal muscles of terrestrial vertebrates. It plays an important role in the organization of movements, enters the system of proprioceptors, participates in the formation of muscle sensation. . ...
- - shortening or tension of the muscles in response to irritation caused by a motor discharge. neurons...
Biological encyclopedic dictionary
- - the common name of V., which are components of muscle tissue ...
Big Medical Dictionary
- - muscular V., which is part of the neuromuscular spindle; peripheral parts of V. of m. have transverse striation and are capable of contraction, the central part does not contract ...
Big Medical Dictionary
- - see Smooth muscle cell ...
Big Medical Dictionary
- - see Muscle fiber intrafusiform ...
Big Medical Dictionary
- - V. m., which is a structural and functional unit of skeletal muscle tissue; consists of a sarcoplasm with numerous nuclei, covered with a sarcolemma, and contains contractile striated myofibrils ...
Big Medical Dictionary
- - see Nervous-...
Big Medical Dictionary
- - see Abbreviation...
Big Medical Dictionary
- - shortening or change in the tension of the muscle fibers that make up the muscle ...
Big Medical Dictionary
- - U., manifested mainly in a certain group of muscles that were subjected to the greatest stress during work ...
Big Medical Dictionary
- - see Kinesthesia...
Big Medical Dictionary
- - a sensation that occurs in the depths of our members and mainly in the muscles, their tendons, in the articular bags and ligaments, and even in the articular parts of the bones, and reaching from there to the centers of the brain in special ...
Encyclopedic Dictionary of Brockhaus and Euphron
- - shortening of the muscle, as a result of which it performs mechanical work. M. s. provides the ability of animals and humans to voluntary movements ...
- - muscular-articular reception, proprioception, the ability of humans and animals to perceive and evaluate changes in the relative position of body parts and their movement ...
Great Soviet Encyclopedia
"Muscle Feeling" in books
Self-esteem is the feeling that you are worthy of love.
From the book of Kryon. 45 practices to learn how to receive the help of the Universe author Liman ArthurSelf-esteem is the feeling that you are worthy of love Kryon says that most people born before 1989 did not have an innate sense of self-worth. But this is not our fault. There are two reasons beyond our control. First
Chapter 14 A Sense of Reality and a Sense of Possibility Why is love still so important to us?
From the book Love author Precht Richard DavidChapter 14 A Sense of Reality and a Sense of Possibility Why is love still so important to us? And I may be responsible to defend Every love, every ending Or maybe I’ve reason to believe We all will be received In Graceland Sex
Subtlety of touch and muscle feeling
From the book Classic Russian Massage in 15 Days author Oguy Viktor OlegovichThe subtlety of touch and muscular sense The subtlety of touch and the degree of development of the muscular sense of the massage therapist play a paramount role in his work. The hand for the massage therapist is his second pair of eyes. And the muscular feeling and the subtlety of touch are significantly weakened by fatigue.
Prolonged muscle tension
From the book Complete Medical Diagnostic Handbook author Vyatkina P.Prolonged muscle tension Symptoms. With so-called tension headaches, people experience a relatively constant feeling of heaviness in the back of the head and forehead, aggravated to a sensation of pain during prolonged fixation of the head (for example, while reading, writing),
Isometric muscle contraction
TSBIsotonic muscle contraction
From the book Great Soviet Encyclopedia (FROM) of the author TSBmuscle contraction
TSBmuscle feeling
From the book Great Soviet Encyclopedia (WE) of the author TSBUncontrolled muscle tension and its treatment
From the book Osteochondrosis author Dolzhenkov Andrey ViktorovichUncontrollable muscle tension and its treatment Repeated physical activity without interruption to stretch the overworked rectifier muscles of the spine eventually leads to uncontrollable residual tension. The disc is constantly compressed
1. Muscle tension
From the book Guide to Systemic Behavioral Psychotherapy author Kurpatov Andrey Vladimirovich1. Muscular tension A. Mental mechanism The above general formula of stress can be successfully applied to a particular case (element) of the body's stress response, namely, to the phenomenon of muscle tension.G. Selye identified two types of stress responses.
Muscle relaxation
author Lagutina TatianaMuscle Relaxation Below we will discuss the technique of progressive muscle relaxation. The techniques described are absolutely reliable, do not cause stress and do not require much physical effort. Exercises are aimed only at the muscles of the hands, forearms, legs and face.
Muscle relaxation with visualization
From the book How to improve memory and develop attention in 4 weeks author Lagutina TatianaMuscle Relaxation with Visualization Yogis have used this exercise to achieve complete relaxation of the body and soul. In addition, it can be used to control the degree of relaxation that you achieve during training. Starting position: lying on your back
CONSISTENT MUSCLE RELAXATION
author Lapp DanielCONSISTENT MUSCLE RELAXATION Do this exercise at home or somewhere in a closed room: when you want to relax, you need to find yourself a secluded corner where you can be alone so that you are not interrupted or disturbed. Purpose of this exercise
MUSCLE RELAXATION WITH VISUALIZATION (USING MENTAL PICTURES)
From the book Improving memory - at any age author Lapp DanielMUSCLE RELAXATION WITH VISUALIZATION (USING MENTAL PICTURES) This exercise is borrowed from yogis - as soon as the muscles relax, they resorted to it for the simultaneous complete relaxation of the body and soul. Therefore, it will be useful to master
3. Sense of proportion, sense of time, algorithms, uniqueness. Aryan science
From the book Our own and others author Khomyakov Petr Mikhailovich3. Sense of proportion, sense of time, algorithms, uniqueness. Aryan science At this point it is worth pausing to describe the fate of our ancestor. Let's take a look at the man who came to the glacial area. Behind him, conflagrations in the subtropics are still smoking. No one has yet
The threshold for the perception of heat and cold is different, for example, thermal points distinguish a temperature difference of 0.2, and cold points of 0.4 ° C. The time it takes to feel the temperature is approximately 1 second. Temperature analyzers, protecting the body from overheating and hypothermia, help maintain a constant body temperature.
AT the skin contains a large number of receptors. Some of them perceive temperature irritations, others - touch and pressure on the skin (tactile). There are especially many of them on the fingertips, in the skin of the palms, on the tip of the tongue, on the lips. Still others perceive painful stimuli. The excitation that has arisen in the skin is transmitted along the sensory nerves and pathways to the brain in the sensitive zone (the region of the parietal lobes), where the corresponding sensation occurs. By irritating the skin with various irritants, four kinds of sensations can be evoked: a feeling of touch and pressure (tactile feeling), a feeling of cold, a feeling of warmth, and a feeling of pain. The combination of tactile, temperature and proprioceptive sensations makes up the sense of touch. Four types of skin sensitivity are due to the presence of various receptors in the skin: tactile - about 500,000, cold - 250,000, thermal - 30,000. Skin sensitivity (except for pain) is projected into the posterior central gyrus of the cerebral cortex.
Tactile receptors allow the brain to determine not only the nature of the stimulus (pressure, heat ...), but also determine the exact location of its impact. There are several types of touch receptors.
AT The skin contains vessels and sensory, motor, vasomotor, sympathetic, and secretory nerves. The endings of sensory nerves are located in the epidermis, thanks to them the perception of pain is carried out. Tactile bodies, or Meissner bodies (corpuscula tactus) (Fig. 415), are located in the papillae of the dermis, are oval in shape and surrounded connective tissue sheath. Their greatest number is observed in the fingertips, the palmar surface of the hands and on the soles. These bodies perceive touch. Tactile menisci - Merkel's discs - are located in the lower layers of the epidermis, consist of epithelial cells and sensitive nerve endings. They also perceive touch and form areas of increased sensitivity (for example, there are a lot of them in the lips). The impact of heat is perceived by Ruffini's little bodies (Fig. 415), and the cold is perceived by Krause's flasks (Fig. 415). Large (from 2 to 4 mm) oval lamellar bodies of Vater-Pacini (corpuscula lamellosa) (Fig. 415) are located in the subcutaneous base, which are able not only to transmit information about touch to the brain, but also to assess the degree of pressure, as a result of which the body reacts to vibration.
Figure 415. Tactile receptors of the skin.
muscle feeling
. For a person, the muscular-articular feeling is important, which allows, with closed eyes, to correctly determine the position of one's body, to find objects. Receptors for the motor analyzer are found in muscles, tendons, ligaments, and on articular surfaces; they are called proprioceptors(from the Latin proprius - own). They send signals to the brain, telling them what state the muscles are in. Through the nerves, excitation from the muscles and joints is transmitted to the sensory-motor zone of the cerebral hemispheres, where a sensation arises that makes it possible to distinguish changes in the position of individual parts and the whole body in space. Thanks to the muscular feeling, the mass and volume of objects are determined, a fine analysis of movements and their coordination is made.nation. In response, the brain sends impulses that coordinate the work of the muscles. Muscular feeling, given the effect of gravity, "works" constantly. Thanks to him, a person takes a more comfortable posture.
If the function of the motor analyzer is impaired, the gait becomes uncertain, shaky, the person loses balance.
Pain sensitivity.
Pain is an alarm signal for the body, a call to fight danger. Pain is perceived by any analyzers if the upper threshold of sensitivity is exceeded, but there are also special receptors in the skin layer - pain. On one square centimeter of skin there are up to 100 pain points - bare nerve endings.Pain can be dangerous, for example, with pain shock, which complicates the body's ability to heal itself.
Pain is caused by defensive reflexes, in particular, the withdrawal reflex from the stimulus. Under the influence of pain, the work of all body systems is rebuilt.
An example of pain sensitivity threshold: 1) abdominal skin - 20 g/mm2; 2) fingertips
300 g/mm2 .
The organ of hearing (Fig. 416) is located in the pyramid of the temporal bone.
Figure 416. The structure of the organ of hearing.
The organ of hearing and balance (vedimentary-cochlear organ) (Fig. 417) contains several types of sensitive cells: receptors that perceive sound vibrations; receptors that detect the position of the head in space; receptors that perceive changes in direction and speed of movement. There are three parts of the organ: the outer, middle and inner ear.
Figure 417. Vestibulo-cochlear organ (organum vestibulo-cochleare). Frontal section through the external auditory meatus. I - auricle; 2 - external auditory meatus; 3 - eardrum; 4 - tympanic cavity; 5 - hammer; 6 - anvil; 7 - stirrup; 8 - vestibule; 9 - snail; 10 - vestibulocochlear nerve; 11 - auditory tube.
The outer ear consists of the auricle and the external auditory canal and is designed to capture and conduct sound vibrations. The auricle is formed by an elastic cartilage of complex shape, covered with skin. It is attached to the temporal bone by ligaments. The external auditory meatus consists of cartilaginous and bony parts. The cartilaginous part is a continuation of the cartilage of the auricle. The external auditory canal is lined with skin and rich in glands that secrete earwax. Its inner end is closed by the tympanic membrane, which is located on the border between the outer and middle ear.
The middle ear lies inside the pyramid of the temporal bone and consists of the tympanic cavity and the auditory (Eustachian) tube connecting the middle ear to the nasopharynx. The middle ear is represented by the tympanic cavity, which communicates with the nasopharynx through the auditory (Eustachian) tube; it is delimited from the outer ear by the tympanic membrane. The components of this department are the hammer, anvil and stirrup (Fig. 418). With its handle, the malleus fuses with the eardrum, while the anvil is articulated with both the malleus and the stirrup, which covers the oval opening leading to the inner ear. In the wall separating the middle ear from the inner ear, in addition to the oval window, there is also a round window covered with a membrane.
Figure 418. Auditory ossicles (ossicula auditis), right. I - hammer; 2 - head of the malleus; 3 - anvil-hammer joint; 4 - anvil; 5 - short leg of the anvil; 6 - long leg of the anvil; 7 - anvil-stapes joint; 8 - stirrup; 9 - rear leg of the stirrup; 10 - stirrup base; 11 - front leg of the stirrup; 12 - hammer handle; 13 - anterior process of the malleus.
The inner ear, or labyrinth (Fig. 419, 420), is located in the thickness of the temporal bone and has double walls: the membranous labyrinth is, as it were, inserted into the bone one, repeating its shape. The slit-like space between them is filled with a transparent liquid - perilymph, the cavity of the membranous labyrinth - endolymph. The labyrinth is represented by the vestibule, anterior to it is the cochlea, posterior to it are the semicircular canals. The cochlea communicates with the middle ear cavity through a round window covered with a membrane, and the vestibule through the oval window.
Figure 419. Bone labyrinth (labyrinthus osseus) of the inner ear; right. Side and front view. 1 - anterior semicircular canal; 2 - anterior bone ampoule; 3 - lateral bone ampoule; 4 - snail; 5 - vestibule; 6 - snail window (round window); 7 - vestibule window (oval window); 8 - posterior bone ampoule; 9 - posterior semicircular canal; 10 - lateral semicircular canal; 11 - common bone pedicle.
Figure 420. Scheme of the relationship between the bony labyrinth and the membranous labyrinth located inside it. The membranous labyrinth is shown in dark green; perilymphatic space - light green. 1 - bone substance of the pyramid of the temporal bone; 2 - posterior semicircular duct; 3 - lateral semicircular duct; 4 - anterior semicircular duct; 5 - ampoules of the semicircular ducts; 6 - endolymphatic sac; 7 - elliptical bag; 8 - endolymphatic duct; 9 - duct connecting the elliptical and spherical sacs; 10 - spherical bag; 11 - cochlear duct; 12 - staircase of the vestibule; 13 - 6apa6annaya ladder; 14 - connecting duct; 15 - snail tubule; 16 - secondary tympanic membrane; 17 - stirrup; 18 - vestibule.
The organ of hearing is the cochlea, the rest of its parts are the organs of balance. The cochlea (Fig. 421) is a spirally twisted canal of 2.75 turns, separated by a thin membranous septum. This membrane is spirally curled and is called the primary.
Figure 421. Scheme of the structure of the cochlear duct. Cross section. 1 - vestibular membrane; 2 - cochlear duct; 3 - vascular strip; 4 - bone wall of the spiral canal of the cochlea; 5 - basilar plate; 6 - spiral (Corti) organ; 7 - outer hair cells of the spiral organ; 8 - cover membrane; 9 - internal tunnel; 10 - nerve fibers; 11 - spiral knot of the cochlea; 12 - inner hair cell.
It consists of fibrous tissue, including about 24 thousand special fibers (auditory strings) of different lengths and located across along the entire course of the cochlea: the longest - at its top, at the base - the most shortened. Above these fibers hang auditory hair cells - receptors. This is the peripheral end of the auditory analyzer, or the organ of Corti. The hairs of the receptor cells face the cavity of the cochlea - the endolymph, and the auditory nerve originates from the cells themselves.
Perception of sound stimuli
(Fig. 422-423). The amount of information received by a person through the organ of hearing is much less than that perceived with the help of the organ of vision (about 10%). However, it is also of great importance in behavior, in the development and formation of personality, in particular, for the development of speech in a child, which has a significant impact on his mental and intellectual development.The organ of hearing has about 23 thousand cells - analyzers, in which sound waves are converted into nerve impulses that go to the brain. The human ear perceives sounds with frequencies ranging from 1620 hertz (Hz) to 20-22 kHz. The intensity of sounds is usually measured in relative units such as bels and decibels (dB).
An important feature of hearing is
binaural effect - possible
direction definition Figure 422. sound. The sound reaches the auricle facing the sound source faster than the other, more distant one. People who are deaf in one ear have no binaural effect. The binaural effect does little to help with sound coming from above.
The vibrations of the stirrup through the membrane of the oval window are transmitted to the perilymph of the vestibule, and through it to the perilymph of the cochlea. Running through its perilymphatic space to the top of the cochlea, they actuate the sound-perceiving apparatus - the spiral (Corti) organ. It is located in the walls of the membranous labyrinth of the cochlea. Receptive cells are located on a membrane that has a different width at the beginning of the cochlea and at its top.
It is believed that as a result of this, the membrane resonates with its different parts in response to sounds of different pitches. Its perceiving cells have microscopic hairs, which, when the membrane vibrates, touch another plate hanging over them in the form of a canopy (integumentary membrane). This is the stimulus for the formation of nerve impulses, which in the future will be transmitted by the VIII cranial nerve to the bridge of the brain, and through its centers and the centers of the diencephalon - to the temporal lobe of the hemisphere, where the cortical center of hearing is located.
Figure 423. Diagram of the propagation of a sound wave (shown by arrows) in the outer; middle and inner ear. I - tympanic membrane; 2 - hammer; 3 - anvil; 4 - stirrup; 5 - round window; 6 - drum stairs; 7 - cochlear duct; 8 - staircase of the vestibule.
vestibular apparatus.
For a number of professions, the state of the vestibular apparatus (Fig. 424) is of particular importance (sailors, pilots, some types of geodetic work, etc.). The vestibular apparatus plays an important role in determining the position of the body in space, its movement and speed of movement. It is located in the inner ear and consists of the vestibule and three semicircular canals located in three mutually perpendicular planes. The semicircular canals are filled with endolymph.Figure 424.
In the endolymph of the vestibule there are two sacs - round and oval with special calcareous stones - statoliths, adjacent to the hair receptor cells of the sacs. The membranous semicircular canals, as well as the sac and the uterus, contain in their walls vestibular receptive cells equipped with hairs. In the spots of the sac and uterus, the hairs are immersed in a special fine-fibrous and jelly-like mass with calcium carbonate crystals (otoliths). At different positions of the head, this mass, due to gravity, acts on the hairs at different angles, which is captured by the receptor cells.