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Sensory system

The human eye , an element of the visual system

Sensory system - a set of peripheral and central structures of the nervous system , responsible for the perception of signals of various modalities from the surrounding or internal environment [1] [2] [3] . The sensory system consists of receptors , neural pathways and brain regions responsible for processing the received signals. The most famous sensory systems are sight , hearing , touch , taste and smell . Using the sensor system, you can feel such physical properties as temperature , taste , sound or pressure .

Also called sensory systems are analyzers. The concept of “analyzer” was introduced by the Russian physiologist I. P. Pavlov [3] . Analyzers (sensory systems) are a set of formations that perceive, transmit and analyze information from the surrounding and internal environment of the body .

Years of life adjusted for disability due to diseases of the sensory organs per 100,000 inhabitants in 2002. [four]
     no data      less than 200      200-400      400-600      600-800      800-1000      1000-1200      1200-1400      1400-1600      1600-1800      1800-2000      2000-2300      more than 2300

Content

General principles of functioning and construction

Sensory systems are divided into external and internal; external ones are equipped with exteroreceptors, internal ones are equipped with interoreceptors. Under normal conditions, the body is constantly undergoing a complex effect, and sensory systems work in constant interaction. Any psychophysiological function is polysensory [5] .

The basic principles of the design of sensor systems include [5] :

  • The principle of multi-channel (duplication in order to increase the reliability of the system)
  • The principle of multilevel information transfer
  • Convergence principle (end branches of one neuron are in contact with several neurons of the previous level; Sherrington funnel )
  • The principle of divergence (animation; contact with several higher-level neurons)
  • The principle of feedbacks (at all levels of the system there is both an upward and a downward path; feedbacks have an inhibitory value as part of the signal processing process)
  • The principle of corticalization (all sensory systems are represented in the new cortex; therefore, the cortex is functionally multi-valued and there is no absolute localization)
  • The principle of bilateral symmetry (exists to a relative degree)
  • The principle of structural-functional correlations (corticalization of different sensory systems has a different degree)

Reaction time

The time of a simple reaction, that is, the time from the moment the signal appeared until the moment the motor response began, was first measured in 1850 by Helmholtz [6] . It depends on which analyzer the signal acts on, on the strength of the signal and on the physical and psychological state of the person. Usually it is equal: to the light of 100-200, to the sound of 120-150 and to the electric skin irritant 100-150 milliseconds. [7]

Information Encoding

Irritability as a property of an organism is the ability to respond, allowing one to adapt to environmental conditions. Irritant can be any chemical-physical change in the environment. The receptor elements of the nervous system make it possible to perceive significant stimuli and transform them into nerve impulses [8] [9] .

The following four characteristics of sensory stimuli are most important [8] :

  • type of
  • intensity (determined by the activity of the lower levels of sensory systems; it is S-shaped, that is, the largest changes in the frequency of the neuron’s pulse occur when the intensity varies in the middle part of the curve, which makes it possible to capture small changes in low-intensity signals — Weber – Fechner law )
  • location (for example, the localization of the sound source occurs due to different arrival times of the sound wave in each ear (for low-frequency signals) or inter-ear differences in stimulation in intensity (for high-frequency signals) [10] ; in any case, the impulse, despite the theoretical possibility of wide divergence, is transmitted according to the principle of a marked line, which allows you to determine the signal source)
  • duration.

In addition to the “principle of the marked line”, lateral inhibition limits the excitation radiation (that is, excited receptors or neurons inhibit neighboring cells, providing contrast) [9] .

The visual system

The visual system provides the function of vision .

The visual system (visual analyzer) in mammals includes the following anatomical formations:

  • peripheral paired organ of vision - the eye (with its light-receiving photoreceptors - rods and cones of the retina );
  • nervous structures and formations of the central nervous system : optic nerves , chiasm , optic tract , optic pathways — the second pair of cranial nerves, the oculomotor nerve — the third pair, the block nerve — the fourth pair and the abducent nerve — the sixth pair;
  • lateral cranked body of the diencephalon (with subcortical visual centers), anterior tubercles of the quadruple of the midbrain (primary visual centers);
  • subcortical (and stem) and cortical visual centers: lateral cranked body and pads of the optic tubercle , upper mounds of the roof of the midbrain (quadruple) and the visual cortex .

An optobiological binocular (stereoscopic) system that evolved in animals, perceiving electromagnetic radiation of the visible spectrum ( light ) and creating an image , simultaneously forms in the form of sensation (sensory feeling ) an idea of ​​the position of objects in space.

Human Vision

The process of psychophysiological processing of images of objects of the surrounding world, carried out by the visual system , and allowing you to get an idea of ​​the size, shape (perspective) and color of objects, their relative position and distance between them. Due to the large number of stages of the process of visual perception, its individual characteristics are considered from the point of view of various sciences - optics (including biophysics), psychology , physiology , chemistry (biochemistry). At each stage of perception, distortions, errors, failures occur, but the human brain processes the information received and makes the necessary adjustments. These processes are unconscious in nature and are implemented in a multilevel autonomous correction of distortions. This eliminates spherical and chromatic aberration, blind spot effects, color correction is performed, a stereoscopic image is formed, etc. In cases where the subconscious processing of information is insufficient or redundant, optical illusions arise.

Hearing Aid

A sensory system that provides coding of acoustic stimuli and determines the ability of animals to navigate in the environment by evaluating acoustic stimuli. The peripheral parts of the auditory system are represented by hearing organs and phonoreceptors lying in the inner ear. On the basis of the formation of sensory systems (auditory and visual), the naming (nominative) function of speech is formed - the child associates objects and their names.

The human ear consists of three parts:

  • The outer ear is the lateral part of the peripheral part of the auditory system of mammals, birds, some reptiles [11] and single species of amphibians [12] [13] [* 1] . In terrestrial mammals, includes the auricle and external auditory canal ; it is separated from the middle ear by the eardrum [11] [14] [15] [16] [17] . Sometimes the latter is considered as one of the structures of the outer ear [18] [19] .
  • The middle ear is part of the auditory system of mammals (including humans), developed from the bones of the lower jaw [20] and provides the conversion of air vibrations into vibrations of the fluid filling the inner ear [21] . The main part of the middle ear is the tympanic cavity - a small space with a volume of about 1 cm³ located in the temporal bone. There are three auditory ossicles: a malleus, an anvil and a stapes - they transmit sound vibrations from the outer ear to the inner, while amplifying them.
  • The inner ear is one of the three parts of the organ of hearing and balance. It is the most complex department of the hearing organs, because of its intricate shape it is called a labyrinth .

The olfactory system

The sensory system of perception of irritations in vertebrates , which perceives, transfers and analyzes olfactory sensations.

  • The peripheral section includes the organs of smell, olfactory epithelium containing chemoreceptors and olfactory nerve . In the paired conducting nerve paths there are no common elements, therefore, a unilateral lesion of the olfactory centers is possible with a violation of the sense of smell on the side of the lesion.
  • The secondary olfactory information processing center is the primary olfactory centers (anterior perforated substance ( lat. Substantia perforata anterior ), lat. Area subcallosa and transparent septum ( lat. Septum pellucidum )) and an additional organ ( vomer perceiving pheromones )
  • The central department - the ultimate center for olfactory information analysis - is located in the forebrain . It consists of an olfactory bulb connected by branches of the olfactory tract with centers located in the paleocortex and in the subcortical nuclei.

Taste system

The sensory system by which taste irritations are perceived. Taste organs - the peripheral part of the taste analyzer, consisting of special sensitive cells (taste buds ). In most invertebrates, the taste organs and the organs of smell are not yet divided and are organs of a common chemical sense - taste and smell . The taste organs of insects are represented by special chitinous hairs - sensilla located on the oral appendages, in the oral cavity, etc. The hair contains supporting cells, they surround receptor cells that give 2 thin processes - peripheral, equipped with a modified cilia, which ends in the pore region and directly adjoins to flavoring substances, and the central, going to the central nervous system. In lower vertebrates , such as fish , the taste organs can be located throughout the body, but especially on the lips, antennae, in the oral cavity, on the branchial arches. In amphibians, the taste organs are only in the oral cavity and partly in the nasal. In mammals, animals and humans, taste organs are located mainly on the papillae of the tongue and partly on the soft palate and posterior wall of the pharynx . The taste organs reach their greatest development in animals that chew food slowly and well.

Somatosensory system

A complex system formed by receptors and processing centers of the nervous system , implementing such sensory modalities as touch , temperature, proprioception , nociception . The somatosensory system also monitors the spatial position of the body parts between themselves. Necessary to perform complex movements controlled by the cerebral cortex . A manifestation of the activity of the somatosensory system is the so-called " muscle feeling ".

Human sensory system

A person has, according to the classification according to the physical energy of the stimulus, which is adequate for this receptor:

  • Chemoreceptors are receptors that are sensitive to chemicals . Each such receptor is a protein complex, which, interacting with a certain substance, changes its properties, which causes a cascade of internal reactions of the body. Among these receptors are sensory receptors ( olfactory and taste buds [22] ) and receptors of the internal state of the body (carbon dioxide receptors of the respiratory center, pH receptors of internal fluids).
  • Mechanoreceptors are the ends of sensitive nerve fibers that respond to mechanical pressure or other deformation acting from the outside, or occurring in internal organs. Among such receptors are Meissner bodies, Merkel bodies, Ruffini bodies, Pacini bodies , muscle spindles , Golgi tendon organs , mechanoreceptors of the vestibular apparatus [23] [24] .
  • Nociceptors are peripheral pain receptors . Intensive stimulation of nociceptors usually causes discomfort and can be harmful to the body [25] . Nociceptors are located mainly in the skin (skin nocireceptors) or in the internal organs (visceral nocireceptors). At the ends of myelinated fibers ( A-type ), they usually respond only to intense mechanical irritation; at the ends of non-myelinated fibers ( C-type ) they can respond to various types of irritations (mechanical, thermal or chemical).
  • Photoreceptors are photosensitive sensory neurons of the retina . Photoreceptors are contained in the outer granular layer of the retina. Photoreceptors respondhyperpolarization (not depolarization , like other neurons) in response to an adequate signal for these receptors is light . Photoreceptors are placed very densely in the retina in the form of hexagons (hexagonal packing) [26] [27] [28] [29] .
  • Thermoreceptors are receptors responsible for temperature reception. The main ones are: Krause cones (giving a feeling of cold) and the already mentioned Ruffini bodies (capable of responding not only to skin stretching, but also to heat) [30] .

A receptive field (field of receptors) is an area in which specific receptors are located that send signals to the associated neuron (or neurons) of a higher synaptic level of a particular sensory system. For example, under certain conditions, the area of ​​the retina , onto which the visual image of the surrounding world is projected, and the only rod or cone of the retina excited by a point source of light can be called a receptive field [31] . At the moment, receptive fields for the visual , auditory and somatosensory systems have been identified.

See also

  • Sensory Filtering
  • Receptive field
  • Characteristics of the human sensory system

Comments

  1. ↑

    Some species, such as Amolops tormotus (Feng et al. 2006), have a cavity in front of the eardrum, which can be considered the external auditory canal, and therefore the external ear.

    Original text
    Some species, like Amolops tormotus (Feng et al. 2006), have a cavity in front of the tympanic membrane which is considered to be an ear canal and thus an outer ear.
    - Schoffelen et al., 2008 [13] .

Notes

  1. ↑ Handverker H. Chapter 8. General sensory physiology // Human physiology: in 3 volumes. T. 1. Per. with English = Human Physiology. Edited by R. F. Schmidt and G. Thews. 2nd, completely revised edition / ed. R. Schmidt and G. Teus (translation under the editorship of Acad. P. G. Kostyuk). - M .: Mir, 1996 .-- 323 p. - ISBN 5-03-002545-6 . - S. 178-196.
  2. ↑ Smirnov V. M., Budylina S. M. Physiology of sensory systems and higher nervous activity: Textbook. allowance for students. higher textbook. institutions. - M .: Publ. Center "Academy", 2003. - 304 p. - ISBN 5-7695-0786-1 . - S. 178-196.
  3. ↑ 1 2 Ostrovsky M. A., Shevelev I. A. Chapter 14. Sensory systems // Human Physiology. Textbook (In two volumes. T. II) / Ed. V. M. Pokrovsky, G. F. Korotko. - M. - 368 p. - (Textbook. Lit. For students of medical universities). - ISBN 5-225-02693-1 . - S. 201—259.
  4. ↑ Mortality and Burden of Disease Estimates for WHO Member States in 2002 (Neopr.) (Xls). World Health Organization (2002). Archived July 30, 2012.
  5. ↑ 1 2 Batuev A. S. Chapter 2. Sensory brain function. § 1. General principles of the construction of sensory systems // Physiology of higher nervous activity and sensory systems. - 3. - St. Petersburg. : Peter, 2010 .-- 317 p. - ISBN 978-5-91180-842-6 . - S. 46-51.
  6. ↑ Helmholtz K. The rate of propagation of nervous excitement. - M .: Politizdat, 1923 .-- 134 p.
  7. ↑ Platonov K. K. Entertaining psychology. - M .: Young Guard, 1964 .-- 384 p.
  8. ↑ 1 2 Batuev A. S. Chapter 2. Sensory brain function. § 2. Patterns of signal detection // Physiology of higher nervous activity and sensory systems. - 3. - St. Petersburg. : Peter, 2010 .-- 317 p. - ISBN 978-5-91180-842-6 . - S. 51-54.
  9. ↑ 1 2 Batuev A. S. Chapter 2. Sensory brain function. § 3. Systemic organization of the processes of coding information // Physiology of higher nervous activity and sensory systems. - 3. - St. Petersburg. : Peter, 2010 .-- 317 p. - ISBN 978-5-91180-842-6 . - S. 54-56 .
  10. ↑ Altman, Y. A. Chapter 5. Spatial hearing // Auditory system / Ed. J. A. Altman. - L .: Nauka, 1990 .-- 620 p. - (Fundamentals of modern physiology). - ISBN 5-02-025643-9 . - S. 366-448.
  11. ↑ 1 2 Gilyarov (eds.), 1998 , p. 393.
  12. ↑ Konstantinov, 1991 , p. 446.
  13. ↑ 1 2 Schoffelen et al., 2008 .
  14. ↑ Weight gain et al., 1985 , p. 627.
  15. ↑ Kraev, 1978 , p. 317.
  16. ↑ Altman, Tavartkiladze, 2003 , p. 31.
  17. ↑ Shuplyakov, 1990 , p. 156.
  18. ↑ Afanasyev et al., 2002 , p. 365-366.
  19. ↑ Bykov, 2001 , p. 227.
  20. ↑ The long animal has become a link in the history of the ear (neopr.) . Date of treatment May 31, 2013. Archived May 31, 2013.
  21. ↑ The functioning of the human ear (hearing) (neopr.) . Biofile Scientific Information Journal. Date of treatment December 5, 2012. Archived December 7, 2012.
  22. ↑ Vorotnikov, 2005 , p. 21.
  23. ↑ The Major Classes of Somatic Sensory Receptors
  24. ↑ Vorotnikov, 2005 , p. 23-24, 28.
  25. ↑ Glossary // Shiffman H.R. Sensation and perception / Per. from English Z. Zamchuk. - 5th ed. - SPb. : Peter, 2003 .-- 928 s. - (Masters of Psychology). - ISBN 5-318-00373-7. - S. 790-833. - S. 811.
  26. ↑ Hubel D. Eye, brain, vision. - M .: Mir, 1990 .-- 240 p.
  27. ↑ Medennikov P.A., Pavlov N.N. Hexagonal pyramid as a model of the structural organization of the visual system // Sensory systems . - 1992. - T. 6, No. 2. - S. 78-83.
  28. ↑ Lebedev D.S., Byzov A. L. Electrical connections between photoreceptors contribute to the allocation of extended boundaries between differently bright fields // Sensor systems . - 1988. - T. 12, No. 3. - S. 329—342.
  29. ↑ Watson AB, Ahumada AJ A hexahonal orthogonal-oriented pyramid as a model of image representation in visual cortex // IEEE Transactions on Biomedical Engineering . - Vol. 36, No. 1. - P. 97-106.
  30. ↑ Vorotnikov, 2005 , p. 28.
  31. ↑ Kolb B., Whishaw I. Q. Fundamentals of Human Neuropsychology. 6th edition. - Basingstoke: Palgrave Macmillan, 2008 .-- 913 p. - ISBN 0-7167-9586-8 .

Literature

  • Altman Ya. A., Tavartkiladze G.A. Guide to Audiology. - M .: DMK Press, 2003 .-- 360 p. - ISBN 5-93189-023-8 .
  • Afanasyev Yu. I., Yurina N.A., Kotovsky E.F. et al. Chapter 12. Sensory systems. Sense organs // Histology, cytology and embryology / Ed. Yu. I. Afanasyev, N. A. Yurina. - M .: Medicine, 2002. - S. 332—378. - 744 p. - ISBN 5-225-04523-5 .
  • Bykov V.L. Hearing and balance organs // Private human histology (short overview course). - SPb. : SOTIS, 2001 .-- S. 227–235. - 304 p. - 40,000 copies. - ISBN 5-85503-116-0 .
  • Biology. Big Encyclopedic Dictionary / Ch. ed. M.S. Gilyarov . - 3rd ed .. - M .: Big Russian Encyclopedia, 1998. - 864 p. - 100,000 copies. - ISBN 5-85270-252-8 .
  • Konstantinov A. I. Chapter 4. Physiology of sensory systems // General course of human and animal physiology. Book 1. Physiology of the nervous, muscular and sensory systems / Ed. A. D. Nozdracheva. - M .: Higher School, 1991. - S. 372-500. - 509 p. - ISBN 5-06-000126-1 .
  • Kraev A.V. The doctrine of sensory apparatus - estesiology // Human Anatomy, in 2 volumes / Ed. R. D. Sinelnikova. - M .: Medicine, 1978. - T. 2. - S. 295—331. - 352 p. - 75,000 copies.
  • Nagel A. Anomalies of refraction and accommodation of the eye / Per. from German V. Dobrovolsky. - SPb. : Printing house of A. S. Suvorin, 1881. - viii + 251 p.
  • Prives M.G., Lysenkov N.K., Bushkovich V.I. Human anatomy / Ed. M. G. Weight. - 9th ed., Revised. and add. - M .: Medicine, 1985 .-- 673 p. - 110,000 copies.
  • Shuplyakov V. S. Chapter 3. Physiology of the peripheral part of the auditory system // Auditory system / Ed. J. A. Altman. - L .: Nauka, 1990 .-- S. 156—223. - 620 s. - (Fundamentals of modern physiology). - 1800 copies. - ISBN 5-02-025643-9 .
  • Imbert A. Les anomalies de la vision. - Paris: J. B. Bailliere et Fils, 1889. - vii + 365 p.
  • Longmore. Guide to the study of vision for military doctors / Per. Lavrentieva. - 1894.
  • Gregg J. Vision experiments at school and at home. - M .: Mir, 1970 .-- 200 p.
  • Gregory R. L. Eye and brain. Psychology of visual perception. - M .: Progress, 1970 .-- 271 p.
  • Molkovsky A. Human Vision . - S .: Slovo, 1983 .-- 347 p.
  • Hubel D. Eye, brain, vision. - M .: Mir, 1990 .-- 239 p. - ISBN 5-03-001254-0 .
  • Gregory R. L. Intelligent Eye. 2nd ed. - M .: URSS editorial, 2003 .-- 240 p. - ISBN 5-354-00342-3 .
  • Vorotnikov S. A. Information devices of robotic systems. - M .: Publishing House of MSTU. N.E. Bauman, 2005 .-- 384 p. - ISBN 5-7038-2207-6 .
  • The auditory system // Human Physiology / Ed. V. M. Pokrovsky, G. F. Korotko. - Medicine, 2007 .-- 656 p. - (Textbooks for medical students). - ISBN 5-225-04729-7 .
  • Batuev A. S. , Kulikov G. A. Introduction to the physiology of sensory systems. - M .: Higher school, 1983.- 247 p.
  • Bradbury J. Taste perception: cracking the code (English) // PLoS Biol. : journal. - 2004 .-- March ( vol. 2 , no. 3 ). - P. E64 . - DOI : 10.1371 / journal.pbio.0020064 . - PMID 15024416 .
  • Smith DV, Margolskee RF Making sense of taste (neopr.) // Sci. Am. . - 2001. - March ( t. 284 , No. 3 ). - S. 32-9 . - DOI : 10.1038 / scientificamerican0301-32 . - PMID 11234504 .
  • Gleason, Michael. Chemoreception ( unopened ) (2004).
  • Watson, Flora. Tarsal Taste Receptors of Flies (Neopr.) (Link unavailable) (2004). Date of treatment May 31, 2013. Archived on September 8, 2006.
  • Schoffelen RLM, Segenhout JM, van Dijk P. Mechanics of the exceptional anuran ear (Eng.) // J Comp Physiol A Neuroethol Sens Neural Behav Physiol. - 2008 .-- Vol. 194 (5). - P. 417-428. - ISSN 0340-7594 . - DOI : 10.1007 / s00359-008-0327-1 . - PMID 18386018 .
  • Scholey JM, Ou G., Snow J., Gunnarson A. Intraflagellar transport motors in Caenorhabditis elegans neurons (Eng.) // Biochem. Soc. Trans. : journal. - 2004 .-- November ( vol. 32 , no. Pt 5 ). - P. 682-684 . - DOI : 10.1042 / BST0320682 . - PMID 15493987 .
  • Augustine, James R. Human Neuroanatomy. - San Diego, CA: Academic Press, 2008 .-- P. 360. - ISBN 978-0-12-068251-5 .
  • Emile L. Boulpaep. Medical Physiology. - Saunders, 2003. - P. 352–358. - ISBN 0-7216-3256-4 .
  • Flanagan, JR, Lederman, SJ Neurobiology: Feeling bumps and holes , News and Views, Nature, 2001 Jul. 26; 412 (6845): 389-391.
  • Hayward V, Astley OR, Cruz-Hernandez M, Grant D, Robles-De-La-Torre G. Haptic interfaces and devices . Sensor Review 24 (1), pp. 16-29 (2004).
  • Purves, Dale. Neuroscience, Fifth Edition. - Sunderland, MA: Sinauer Associates, Inc, 2012. - P. 202-203. - ISBN 978-0-87893-695-3 .
Source - https://ru.wikipedia.org/w/index.php?title=Sensory_system&oldid=101061497


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