Sense organs analyze their structure and functions. Human Analyzers
The analyzer is a part of the nervous system that perceives the effects of external stimuli, transforms them into a nerve signal, transmits this signal to the brain and analyzes it there. Each analyzer is associated with one type of perceived energy.
Analyzer structure
The doctrine of analyzers was created by I. P. Pavlov. He was the first to consider the analyzer as a single system, consisting of three parts:
- receptor department;
- conductor department;
- central department
Rice. 1. Analyzer circuit.
Table “Human Analyzers”
The visual analyzer supplies the largest amount of information to the body. The second most important is auditory.
The vestibular analyzer provides a person’s orientation in space and a sense of balance. Its receptors are located inside the head, in the temporal bone.
Receptors
Receptors are sensitive cells that have the ability to perceive irritations and convert them into a nerve impulse. They are located in the senses. Depending on the stimulus they perceive, The following types of receptors are distinguished:
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- photoreceptors;
- chemoreceptors;
- mechanoreceptors;
- thermoreceptors.
Rice. 2. Human photoreceptors under a microscope.
Photoreceptors perceive light energy and are part of the visual analyzer.
Chemoreceptors form the perceptive part of the taste and olfactory analyzers. They convert the effects of chemicals into a nerve impulse.
The sensation of taste occurs only when the substance dissolves in saliva. If the tongue is dried and sugar is placed on it, a person will not feel its taste until the sugar is moistened with saliva.
Mechanoreceptors perceive the effects of mechanical stimuli. They are part of the human auditory, tactile and vestibular analyzers.
The conductive part of the analyzers directs the impulse to the central section. Thus, the optic nerve transmits nerve impulses from photoreceptors to the brain. The auditory nerve transmits information from the auditory receptors in the ear to the brain.
In the central sections of the analyzers, the received information is analyzed and sensations are formed.
Rice. 3. Sensory areas of the cerebral cortex.
It is precisely due to the fact that nerve impulses enter different areas of the brain that there is no confusion in their rich flow.
Functions
The following processes are carried out in turn in the analyzers:
- signal detection;
- signal discrimination;
- transmission and conversion of signals;
- signal recognition;
- pattern recognition.
The purpose of the transmission and transformation processes is to convey information to the brain in a convenient form. Therefore, only important information is selected, unnecessary information is eliminated.
Pattern recognition is the final operation of the analyzer. A person recognizes an image, assigns it to a category, considers it important or unimportant.
What have we learned?
While studying this topic in 8th grade, we found out the structure and functions of analyzers. Any analyzer consists of receptors, conducting nerves and a part of the brain where the incoming information is analyzed. Analyzers of human feelings interact with memory, which stores already known images.
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A healthy man in your home Elena Yuryevna Zigalova
Analyzers (sense organs)
Analyzers (sense organs)
The sense organs communicate the body with the external environment. It is the sense organs that are the “entrance gates” to the human psyche, consciousness and thinking. In 1912, the great physiologist Nobel Prize laureate I.P. Pavlov formulated a fundamentally new concept - analyzers, with which he replaced the generally accepted term “sense organs”. Normal functioning of the body is possible in the presence of three conditions: constancy of the internal environment (homeostasis), constant connection with continuously changing environmental conditions and adaptation (adaptation) to it. Please pay attention! All information about the state of the external and internal environment enters the body through analyzers.
But first, let’s talk about analyzers. Analyzer(according to I.P. Pavlov) is a complex of structures that perceive signals from the external and internal environment, convert their energy into a nerve impulse, and produce higher analysis and synthesis.
Each analyzer consists of three parts: peripheral (actually one of the sense organs), pathways and cortical center.
In the peripheral part the main structure is the receptor cell, which perceives external irritation and processes its energy into a nerve impulse. The peripheral part also includes auxiliary structures that provide optimal perception (for example, in the eye - lens, muscles, etc.). By conductive paths the nerve impulse follows to the nerve center. Neurons of the cortical end of the analyzer analyze information, reconstruct it and compare it. Signals from various analyzers are combined with information stored in memory.
A person has six analyzers that perceive external stimuli (visual, auditory, balance, gustatory, olfactory and tactile). Internal analyzers perceive and analyze changes in parameters of the internal environment (for example, blood pressure, the content of various substances in the blood).
Any sensation has four parameters: spatial, temporal, intensity (or quantity) and quality (or modality). Each analyzer responds optimally only to certain adequate stimuli. However, the specificity of analyzers is related to the specificity of receptors and the nature of central information processing (Table 1.8).
Table 1.8. The main categories in the field of sensory processes are modality and quality (according to F. Bloom et al. with modifications)
Previous experience plays an important role in perception. Environmental stimuli are interpreted by the brain taking into account accumulated information. If the information is new or incomplete, the brain puts forward a certain hypothesis (J. Godefroy, 1992). The surrounding world is perceived in three dimensions, thanks to the presence of paired symmetrically located sense organs. In addition, a person perceives movement and time, the latter has limits from 1/18 to 2 s.
In the central nervous system, where nerve impulses arrive, all information is processed in the brain structures responsible for articulate speech. As a result, there arises perception– the ability to see, hear, touch, taste, smell and position the body in space.
From the book Propaedeutics of Childhood Illnesses by O. V. Osipova by O. V. Osipova From the book Propaedeutics of Childhood Illnesses: Lecture Notes by O. V. Osipova From the book The Female Brain and the Male Brain by Serge Ginger From the book Secrets of our Brain by Sandra Amodt From the book Latin Terminology in the Course of Human Anatomy author B. G. Plitnichenko From the book Atlas: human anatomy and physiology. Complete practical guide author Elena Yurievna Zigalova From the book Set Up for Healing author From the book Beyond the Possible author Alexander Vladimirovich Likhach From the book Disease as a Path. The meaning and purpose of diseases by Rudiger DahlkeVisual sensory system. Organ of hearing and balance. Smell and taste analyzers. Cutaneous sensory system.
The human body as a single whole is a unity of functions and forms. Regulation of the body's life support, mechanisms for maintaining homeostasis.
Topic for independent study: Structure of the eye. Structure of the ear. The structure of the tongue and the location of sensitivity zones on it. The structure of the nose. Tactile sensitivity.
Sense organs (analyzers)
A person perceives the world around him through the senses (analyzers): touch, sight, hearing, taste and smell. Each of them has specific receptors that perceive a certain type of irritation.
Analyzer (sense organ)- consists of 3 sections: peripheral, conduction and central. Peripheral (perceiving) link analyzer - receptors. They transform signals from the outside world (light, sound, temperature, smell, etc.) into nerve impulses. Depending on the method of interaction of the receptor with the stimulus, there are contact(skin, taste receptors) and distant(visual, auditory, olfactory) receptors. Conductor link analyzer - nerve fibers. They conduct excitation from the receptor to the cerebral cortex. Central (processing) link analyzer - a section of the cerebral cortex. A malfunction of one part causes a malfunction of the entire analyzer.
There are visual, auditory, olfactory, gustatory and skin analyzers, as well as a motor analyzer and a vestibular analyzer. Each receptor is adapted to its own specific stimulus and does not perceive others. Receptors are able to adapt to the strength of the stimulus by reducing or increasing sensitivity. This ability is called adaptation.
Visual analyzer. Receptors are excited by light quanta. The organ of vision is the eye. It consists of the eyeball and an auxiliary apparatus. Auxiliary apparatus represented by eyelids, eyelashes, lacrimal glands and muscles of the eyeball. Eyelids formed by folds of skin lined from the inside with mucous membrane (conjunctiva). Eyelashes protect the eyes from dust particles. Lacrimal glands located in the outer upper corner of the eye and produce tears that wash the front of the eyeball and enter the nasal cavity through the nasolacrimal duct. Muscles of the eyeball set it in motion and orient it towards the object in question.
Eyeball located in the orbit and has a spherical shape. It contains three shells: fibrous(external), vascular(average) and mesh(internal), as well as inner core, consisting of lens, vitreous And aqueous humor anterior and posterior chambers of the eye.
The posterior part of the fibrous membrane is a dense opaque connective tissue tunica albuginea (sclera), front - transparent convex cornea. The choroid is rich in blood vessels and pigments. It actually distinguishes choroid(rear end), ciliary body And iris. The bulk of the ciliary body is the ciliary muscle, which changes the curvature of the lens through its contraction. Iris ( iris) has the appearance of a ring, the color of which depends on the amount and nature of the pigment it contains. There is a hole in the center of the iris - pupil. It can contract and expand due to the contraction of muscles located in the iris.
The retina has two parts: rear- visual, perceiving light stimuli, and front- blind, not containing photosensitive elements. The visual part of the retina contains light-sensitive receptors. There are two types of visual receptors: rods (130 million) and cones (7 million). Sticks are excited by weak twilight light and are unable to distinguish color. Cones are excited by bright light and are able to distinguish color. The rods contain red pigment - rhodopsin, and in cones - iodopsin. Directly opposite the pupil there is yellow spot - the place of best vision, which contains only cones. Therefore, we see objects most clearly when the image falls on the yellow spot. Towards the periphery of the retina, the number of cones decreases, and the number of rods increases. Only sticks are located along the periphery. The place on the retina from which the optic nerve emerges is devoid of receptors and is called blind spot.
Most of the cavity of the eyeball is filled with a transparent gelatinous mass, forming vitreous body, which maintains the shape of the eyeball. Lens It is a biconvex lens. Its back part is adjacent to the vitreous body, and its front part is facing the iris. When the muscle of the ciliary body associated with the lens contracts, its curvature changes and light rays are refracted so that the image of the object of vision falls on the macula of the retina. The ability of the lens to change its curvature depending on the distance of objects is called accommodation. If accommodation is disturbed, there may be myopia(the image is focused in front of the retina) and farsightedness(the image is focused behind the retina). With myopia, a person sees distant objects unclearly, with farsightedness - near objects. With age, the lens hardens, accommodation deteriorates, and farsightedness develops.
On the retina, the image appears inverted and reduced. Thanks to the processing in the cortex of information received from the retina and receptors of other senses, we perceive objects in their natural position.
Hearing analyzer. The receptors are excited by sound vibrations in the air. The organ of hearing is the ear. It consists of the outer, middle and inner ear. Outer ear consists of the auricle and auditory canal. Ears serve to capture and determine the direction of sound. External auditory canal begins with the external auditory opening and ends blindly eardrum, which separates the outer ear from the middle ear. It is lined with skin and has glands that secrete earwax.
Middle ear consists of the tympanic cavity, auditory ossicles and auditory (Eustachian) tube. Tympanic cavity filled with air and connected to the nasopharynx by a narrow passage - auditory tube, through which the same pressure is maintained in the middle ear and the space surrounding the person. Auditory ossicles - hammer, anvil And stirrup - movably connected to each other. Vibrations from the eardrum are transmitted through them to the inner ear.
Inner ear consists of a bony labyrinth and a membranous labyrinth located in it. Bone labyrinth contains three sections: vestibule, cochlea and semicircular canals. The cochlea belongs to the organ of hearing, the vestibule and semicircular canals belong to the organ of balance (vestibular apparatus). Snail- a bone canal twisted in the form of a spiral. Its cavity is divided by a thin membranous septum - the main membrane on which receptor cells are located. The vibration of the cochlear fluid irritates the auditory receptors.
The human ear perceives sounds with a frequency from 16 to 20,000 Hz. Sound waves reach the eardrum through the external auditory canal and cause it to vibrate. These vibrations are amplified (almost 50 times) by the ossicular system and transmitted to the fluid in the cochlea, where they are perceived by auditory receptors. The nerve impulse is transmitted from the auditory receptors through the auditory nerve to the auditory zone of the cerebral cortex.
Vestibular analyzer. The vestibular apparatus is located in the inner ear and is represented by the vestibule and semicircular canals. vestibule consists of two bags. Three semicircular canals located in three mutually opposite directions corresponding to three dimensions of space. Inside the sacs and channels there are receptors that are able to sense fluid pressure. The semicircular canals perceive information about the position of the body in space. The bags perceive deceleration and acceleration, changes in gravity.
Excitation of the receptors of the vestibular apparatus is accompanied by a number of reflex reactions: changes in muscle tone, contraction of muscles that help straighten the body and maintain posture. Impulses from the receptors of the vestibular apparatus travel through the vestibular nerve to the central nervous system. The vestibular analyzer is functionally connected to the cerebellum, which regulates its activity.
Taste analyzer. Taste buds are irritated by chemicals dissolved in water. The organ of perception is taste buds- microscopic formations in the oral mucosa (on the tongue, soft palate, posterior pharyngeal wall and epiglottis). Receptors specific to the perception of sweet are located at the tip of the tongue, bitter - on the root, sour and salty - on the sides of the tongue. With the help of taste buds, food is tasted, its suitability or unsuitability for the body is determined, and when they are irritated, saliva and gastric and pancreatic juices are released. The nerve impulse is transmitted from the taste buds through the taste nerve to the taste zone of the cerebral cortex.
Olfactory analyzer. Smell receptors are irritated by gaseous chemicals. The sensory organ is the sensory cells in the nasal mucosa. The nerve impulse is transmitted from the olfactory receptors through the olfactory nerve to the olfactory zone of the cerebral cortex.
Skin analyzer. Skin contains receptors , perceiving tactile (touch, pressure), temperature (heat and cold) and pain stimuli. The organ of perception is the receiving cells in the mucous membranes and skin. The nerve impulse is transmitted from tactile receptors through the nerves to the cerebral cortex. With the help of tactile receptors, a person gets an idea of the shape, density, and temperature of bodies. There are most tactile receptors on the tips of the fingers, palms, soles of the feet, and tongue.
Motor analyzer. Receptors are excited when muscle fibers contract and relax. The organ of perception is the sensory cells in muscles, ligaments, and on the articular surfaces of bones.
Sense organs are specialized structures through which parts of the brain receive information from the internal or external environment. With their help, a person is able to perceive the world around him.
Sense organs - afferent (receptive) section of the analyzer system. The analyzer is the peripheral part of the reflex arc, which communicates between the central nervous system and the environment, receives irritation and transmits it through pathways to the cerebral cortex, where information is processed and sensation is formed.
5 human senses
How many primary senses does a person have?
In total, a person usually has 5 senses. Depending on their origin, they are divided into three types.
- The organs of hearing and vision come from the embryonic neural plate. These are neurosensory analyzers, they belong to first type.
- The organs of taste, balance and hearing develop from epithelial cells, which transmit impulses to neurocytes. These are sensory epithelial analyzers and belong to second type.
- Third type includes peripheral parts of the analyzer that sense pressure and touch.
Visual analyzer
The main structures of the eye: the eyeball and auxiliary apparatus (eyelids, muscles of the eyeball, lacrimal glands).
The eyeball has an oval shape, is attached by ligaments, and can move with the help of muscles. Consists of three shells: outer, middle and inner. Outer shell (sclera)- this protein shell of an opaque structure surrounds the surface of the eye by 5/6. The sclera gradually passes into the cornea (it is transparent), which makes up 1/6 of the outer shell. The transition area is called the limb.
Middle shell consists of three parts: the choroid, the ciliary body and the iris. The iris has a colored color, in the center of it there is a pupil, thanks to its expansion and contraction, the flow of light to the retina is regulated. In bright light, the pupil narrows, and in low light, on the contrary, it expands to catch more light rays.
Inner shell- this is the retina. The retina is located at the bottom of the eyeball and provides light and color perception. The photosensory cells of the retina are rods (about 130 million) and cones (6-7 million). Rod cells provide twilight vision (black and white), while cones provide daytime vision and color discrimination. The eyeball contains a lens and chambers of the eye (anterior and posterior).
The value of the visual analyzer
With the help of the eyes, a person receives about 80% of information about the environment, distinguishes colors and shapes of objects, and is able to see even with minimal light. The accommodative apparatus makes it possible to maintain clarity of objects when looking into the distance or reading closely. Auxiliary structures protect the eye from damage and contamination.
Hearing analyzer
The organ of hearing includes the outer, middle and inner ear, which perceive sound stimuli, generate an impulse and transmit it to the temporal cortex. The auditory analyzer is inseparable from the organ of balance, so the inner ear is sensitive to changes in gravity, vibration, rotation, and movement of the body.
Outer ear It is divided into the auricle, auditory canal and eardrum. The auricle is an elastic cartilage with a thin ball of skin that detects sound sources. The structure of the external auditory canal includes two parts: cartilaginous at the beginning and bone. Inside there are glands that produce sulfur (has a bactericidal effect). The eardrum perceives sound vibrations and transmits them to the structures of the middle ear.
Middle ear includes the tympanic cavity, inside which are located the hammer, stirrup, incus and Eustachian tube (connects the middle ear with the nasal part of the pharynx, regulates pressure).
Inner ear It is divided into a bony and membranous labyrinth, with perilymph flowing between them. The bony labyrinth has:
- vestibule;
- three semicircular canals (located in three planes, provide balance, control the movement of the body in space);
- cochlea (it contains hair cells that perceive sound vibrations and transmit impulses to the auditory nerve).
The value of the auditory analyzer
Helps to navigate in space, distinguishing noises, rustles, sounds at different distances. With its help, information is exchanged when communicating with other people. From birth, a person, hearing oral speech, learns to speak. If congenital hearing impairment occurs, the child will not be able to speak.
The structure of the human olfactory organs The receptor cells are located at the back of the upper nasal passages. Perceiving odors, they transmit information to the olfactory nerve, which delivers it to the olfactory bulbs of the brain.
With the help of smell, a person determines the good quality of food, or senses a threat to life (carbon smoke, toxic substances), pleasant aromas lift the mood, the smell of food stimulates the production of gastric juice, promoting digestion.
Organs of taste
On the surface of the tongue there are papillae - these are taste buds, on the apical part of which there are microvilli that perceive taste.
The sensitivity of receptor cells to food products is different: the tip of the tongue is susceptible to sweets, the root to bitter, the central part to salty. Through nerve fibers, the generated impulse is transmitted to the overlying cortical structures of the taste analyzer.
Organs of touch
A person can perceive the world around him through touch, with the help of receptors on the body, mucous membranes, and muscles. They are able to distinguish temperature (thermoreceptors), pressure levels (baroreceptors), and pain.
Nerve endings have high sensitivity in the mucous membranes and earlobe, and, for example, the sensitivity of receptors in the back area is low. The sense of touch makes it possible to avoid danger - to remove your hand from a hot or sharp object, determines the degree of pain threshold, and signals an increase in temperature.
Structure of the eyeEyeball with
optic nerve
The eyeball consists of
3 shells that
surround the inner core
eyes representing him
transparent content -
vitreous body,
lens, watery
moisture in front and rear
cameras.
Vitreous body -
jelly-like structure,
99% water and 1%
hyaluronic acid.
Structure of the eye
Three layers of the eyeball: outer, middle and innerOutdoor
fibrous
(connector
nonwoven)
),
External ones are attached
muscles of the eye
apple,
protective function,
determines
eye shape
Anterior cornea
transparent part.
Sclera - posterior
opaque
Part.
Average,
or
vascular,
shell
plays an important role
in exchange
processes,
provides
eye nutrition,
excretion
products of exchange.
Internal
or
mesh
retina -
receptor part
visual
analyzer The retina is the receptor part of the visual
analyzer, apple.
The retina is a thin layer of nerve tissue
on the inside of the back of the eyeball.
Receptor cells (photoreceptors) - two types:
cones and rods.
Cones (7 million) - only in bright conditions
lighting and are capable of transmitting color perception.
Iodopsin is a visual pigment that allows
perceive colors in daylight.
Cones - three types with spectral
sensitivity to red, green or blue
blossom. In the central part of the retina
called the corpus luteum.
Rods (140 million) are cylindrical formations.
Provides vision in low light,
for example, at night, having a very high light
sensitivity.
Distribution of photoreceptors in
different areas of the retina
Pigment – rhodopsin, perceives crepuscular
unequal: highest density
light without distinguishing the colors of objects.
cones in the central zone.
Further to the periphery the density
cones are reduced. Retinal functions
Perception of light
Biochemical transformations of visual pigments
Changes in the electrical properties of neurons
Transfer of information to the central nervous system.
Optic nerve
Receptors
retina
Visual
cortical zone Myopia and farsightedness Hearing organs
The ear is divided into three parts:
the outer ear, which picks up sound like radar;
the middle ear, in which a set of bones amplifies the resulting sound;
inner ear, which converts sound vibrations into electrical vibrations
impulses and determines what position the head is in.
External - auricle and
ear canal, which
ends with the eardrum.
Middle - pneumatic drum
cavity that passes into the auditory
(Eustachian) tube (and three auditory
bones - hammer, stirrup and
anvil.
Internal - membranous labyrinth,
which contains the cochlea (organ
hearing) and vestibular apparatus.,
All cavities are filled with liquid. Sound wave
Brain
Koleblet
Transmitted
Drum
membrane
Nerve impulse
Koleblet
Arises
Receptor cells
with hairs
Auditory ossicles
The stirrup oscillates
Koleblet
Membrane oval
Window
Koleblet
Fluid in the cochlea
How does the ear hear?
Who hears what?The number of oscillations, or cycles, in
second is frequency: than
The more vibrations, the higher the sound.
The frequency of sound is expressed as a number
cycles per second, or in hertz (Hz).
A person is able to perceive
sound vibrations from 16 Hz (16
oscillations per second) up to 21,000 Hz.
With age, this value
decreases two to three times - up to 5000 Hz.
Some animals are capable
perceive fluctuations up to 20 - 30
thousand Hz, for example bats - up to
210,000 Hz, dolphins - up to 280,000 Hz.
The units of measurement indicated below are
hertz (thousands of hertz on the left side of the scale). The vestibular apparatus is an organ that perceives changes in the position of the head and body in
space and direction of body movement in vertebrates and humans.
It is part of the inner ear.
The vestibular apparatus consists of two
pouches - Elliptical and Spherical and
three semicircular canals.
One of the legs of the ducts expands to form -
ampoules.
Sections of the wall of the sacs with receptor cells
cells - spots.
The function of the semicircular canals determines the angular (rotational)
acceleration of the head in all planes (with
turning, nodding, rocking from side to side
side).
The elliptical sac (uterus) plays
a leading role in the perception of body position and,
probably involved in the sensation of rotation.
The spherical sac (sacculus) complements
oval and apparently necessary for
perception of vibrations.
Vestibular apparatus
The nose is an organ of the respiratory system, namely through the nasal passagesair enters other organs of the upper respiratory tract. Air
masses entering the nasal cavity are cooled or warmed,
are moistened and only after that are redirected to the underlying departments
respiratory system. It is in the nasal cavity that the olfactory senses are located.
receptors through which the primary assessment of odors occurs.
Olfactory organ - nose
Smells
Limbic system - totalitya number of brain structures.
Envelops the top of the trunk
brain.
Nuclei of the anterior thalamus
Hypothalamus
Amygdala (amygdala)
Hippocampus
Olfactory bulb
Cingulate gyrus
Mamillary bodies.
Mechanism of odor transmission
Sense of tasteThe sense of taste is the most primitive
of the five human senses.
Limited in range, in
versatility, less
information about the surrounding world.
The role of this feeling is to choose and
evaluate food and drinks
Taste organ formed ~2000
taste buds.
There are four taste buds
basic tastes: sweet, sour,
salty and bitter. SKIN IS THE ORGAN OF TOUCH
Skin is the outer covering of the human body with an area of 1.5
- 2 m2. Consists of two layers: epidermis and dermis, under
which contains subcutaneous fatty tissue.
Performs multiple functions: protective,
thermoregulatory, respiratory, metabolic, receptor.
Skin glands produce sweat and sebum. SKIN – Epidermis
The epidermis has ectodermal
origin, separated from dermis
basement membrane.
There are 5 layers in the epidermis:
1 - basal (Malpighian),
represented by fission and
pigment cells with
melanin;
2 - spinous, cells
connected by numerous
shoots;
3 - granular, contains granules
keratohyalin protein;
4 - shiny, cell nuclei of this
layers are destroyed;
5 - horny, educated
dead cells
containing keratin.
Nails, claws, antlers (except for the antlers of deer and giraffes), feathers, hair, horny
scales are derivatives of the epidermis in amniotes (higher vertebrates). Dermis or skin itself
In the dermis there are
two layers: -
papillary, due to
whose papillae
scallops are formed
and grooves,
is being formed
papillary
drawing
mesh, in which
collagen and
elastic fibers
form a network.
The dermis contains blood and lymphatic vessels, nerve
endings, sweat and sebaceous glands, hair. Below is the subcutaneous
fatty tissue.
The sweat, sebaceous and mammary glands are derivatives of the DERMA. Structure of the skin - glands
Mammary glands - derivatives
sweat glands
Sweat glands (about
2.5 million) - long
tubes, initial part
twisted into a ball
pores open.
Responsible for
thermoregulation, remove
water, NaCl, urinary
acid, ammonia, urea.
Sebaceous glands
open into the hairline
bag. Sebum
lubricates skin and hair. IN
composition of fatty acids,
waxes, steroids.
Water-repellent layer
defence from
microorganisms. Skin structure - hair
Hair consists of a shaft and a root.
The root forms the hair
the bulb into which the papilla protrudes,
nourishing hair.
Located in the epithelial
vagina surrounded
connective tissue bag, to
to which smooth muscle is attached.
The vagina and bursa form
hair follicle in which
there is hair.
The hair shaft consists of
medulla and cortex,
containing the pigment melanin. Skin structure - hair
The outside of the hair is covered with horny
scales.
Decreases with age
amount of pigment in the cortex
layer and the amount increases
air in the medulla
hair turns grey.
Hair loss is associated with
atrophy of the lower part
hair follicle, but even before
hair loss
epithelial vagina
surrounds the hair papilla and
new hair begins to grow. Skin functions
Skin reception: about 200 pain per 1 cm2 of skin
receptors, 15 cold ones, closer to the surface,
than thermal, 1-2 thermal, 25 tactile.
Protective: protection from mechanical damage,
impenetrable to microorganisms, protection against excess
ultraviolet radiation through the formation of melanin.
The excretory function is carried out due to the work
sweat and sebaceous glands. A person loses about 1000 ml per day
sweat with dissolved salts and products of protein metabolism.
Respiratory function - up to 1.5% of total gas exchange
falls on the skin.
Formation of vitamin D under the influence of ultraviolet light
rays.
Storage of energy materials in subcutaneous fat
fiber. Skin functions
Regulation of heat transfer by changing intensity
sweating (in hot weather during heavy physical work, the body
can lose up to 12 liters of fluid due to sweating) and with the help
changes in the speed of blood flow in the skin.
Blood flow can vary from 1 ml/min to 100 ml/min, heat transfer
increases by 5-6 times. Below the level of the capillary network there are “shunts”, with
narrowing of which blood passes below the capillary network.
Subcutaneous fat plays a heat-insulating role. Skin hardening effect
Regular hardening adapts the body to rapid
restructuring of metabolism, to a change in heat transfer due to
changes in blood flow through the skin and changes in intensity
sweating.
When there is a disease of the internal organs, sensitivity is impaired
skin in an area strictly corresponding to a specific organ. Sixth Sense
(but actually the seventh) -
colloquial name for any
feelings of a person or animal,
in addition to the five “basic” ones: vision,
hearing, smell, touch and
senses of taste.
In particular, the hypothetical
extrasensory feeling. IN
may exist in different contexts
meaning telepathy, intuition,
clairvoyance, etc.
From an anatomical point of view
human - sense of balance
(organ – vestibular apparatus
located in the middle
(inner) ear. Analyzer centers in the brain
29Alalia - damage
large speech areas
cerebral hemispheres
during childbirth, as well as brain
illness or injury,
suffered by the child
in the pre-speech period of life.
BROCCA'S AREA (ARTICULATION)
in honor of the French surgeon Paul Broca (1865);
located in the inferior frontoparietal
parts of the left hemisphere in right-handed people and
the right hemisphere - for left-handers;
controls the muscles of the face, tongue,
pharynx, jaws;
responsible for motor reproduction
speech - articulation;
Broca - impossibility of unification
separate speech movements into a single
speech act;
the lower parts are also responsible for articulation
sections of the dominant hemisphere,
premotor and prefrontal
sections of the cortex.
ALALIA - underdevelopment or absence of speech
WERNICKE'S AREA (PERCEPTION)in honor of him. neurologist and psychiatrist
Carla Wernicke
sensory auditory-speech zone of the cortex auditory-speech analyzer
located in the superior posterior part of the temporal
part of the cortex of the left hemisphere in right-handed people
Aphasia - local
and the right hemisphere in left-handed people;
absence or violation
converts auditory signals into
already formed
neural codes, cat. activate resp.
speech (as opposed to alalia).
images
With organic
responsible for speech perception and processing
lesions of the speech departments
when damaged, aphasia occurs
cerebral cortex in
Wernicke - inability to perceive
as a result of the transferred
speech sounds as linguistically significant;
injuries, tumors, strokes,
and with some mental illnesses a person is unable to perceive speech
diseases.
or written text;
APHASAIA – inability to perceive speech
SENSE ORGANS AND BRAIN Brown eyes are actually blue under the brown pigment.The cornea of the human eye is so similar to the cornea of a shark that the latter
used as a substitute for eye surgeries.
The fact is that you cannot sneeze with your eyes open.
Our eyes can distinguish about 500 shades of gray.
Each eye contains 107 million cells, all of which are sensitive to light.
The human eye sees only three colors: red, blue and green. The rest are
combination of these colors.
We see with our brains, not with our eyes. In many cases, blurry or poor vision is not caused by
eyes, but problems with the visual cortex of the brain.
The images that are sent to our brain are actually upside down.
The eyes use about 65 percent of the brain's resources. This is more than any other part
bodies.
Your fingerprints have 40 unique characteristics, while the rainbow
membrane of the eye - 256. It is for this reason that retinal scanning is used for
security.
About 10,000 years ago, all people had brown eyes, until a person living in the area
Black Sea, the genetic mutation that led to the appearance of blue eyes did not appear.
Most people with blue eyes are in the Baltic countries and
Nordic countries. In Estonia, 99 percent of people are
owners of blue eyes.
Only 1-2 percent of people in the world own green
eye. After a hearty lunch, we hear worse.
Only one third of all people have 100% vision.
If saliva can't dissolve something, you won't taste it.
From birth, women have a better developed sense of smell than men.
The nose remembers 50,000 different aromas.
The pupils dilate even due to slight interference.
All people have their own unique smell.
By the age of sixty, most people have lost about half
taste buds.
The eyes are the same size all their lives, but the nose and ears grow throughout their lives.
A case has been reported of conjoined twins from Canada who share
thalamus. Thanks to this, they could hear each other's thoughts and see
each other's eyes.
To keep an eye on nocturnal predators, many animal species (ducks,
dolphins, iguanas) sleep with one eye open. One half
one hemisphere of their brain is asleep while the other is awake.
