Sense

Senses are the physiological methods of perceptionpostrzeganie. The senses and their operation, classification, and theory are overlappingnachodzący na siebie, pokrywający się topics studied by a variety of fields, but most notably neurosciencenauka zajmująca się badaniem układu nerwowego, cognitive psychology (or cognitive science), and philosophy of perceptionpostrzeganie.

Definition of "sense"

There is no firmmocny, pewny, stanowczy agreement amongst neurologists as to exactly how many senses there are. The disagreements stem from a lack of consensus as to what the definition of a sense should be. Although school children are still routinelyrutynowo taught that there are five senses (sight, hearing, touch, smell, taste; a classification first devisedto devise: obmyślać, wynaleźć by Aristotle), it is generally agreed that there are at least nine different senses in humans, and a minimum of two more observed in other organisms.

A broadly acceptable definition of a sense would be "a system that consists of a sensory cellkomórka czuciowa type (or group of cell types) that respond to a specific kind of physical energy, and that correspond to a defined region (or group of regions) within the brain where the signals are received and interpreted". Where disputes arise is with regard tojeśli chodzi o, co się tyczy the exactdokładny, skrupulatny classification of the various cell types and their mappingodwzorowanie to regions of the brain.

List of senses

Using this definition several senses can be identified. This list begins with those five senses defined by Aristotle and hencedlatego, stąd probably most familiar to the reader.

Seeing or vision describes the ability to detectwykrywać, wyczuwać light by the eye and the brain to interpret the image as "sight". There is disagreement as to whether or not this constitutesto constitute: tworzyć, stanowić, składać się na one, two or even three distinctróżny, odrębny senses. Neuroanatomists generally regard it as two senses, given that different receptors are responsible for the perceptionpostrzeganie of colour (the frequencyczęstotliwość, częstość of light) and brightnessjasność, jaskrawość (the energy of light). Some argue that the perceptionpostrzeganie of depthgłębia also constitutesto constitute: tworzyć, stanowić, składać się na a sense, but it is generally regarded that this is really a cognitive (that is, post-sensory) function derived fromto derive from: pochodzić z, wywodzić się having stereoscopic visionwidzenie stereoskopowe, przestrzenne (two eyes) and is not a sensory perceptionpostrzeganie as such.

Hearing or audition is the sense of sound perceptionpostrzeganie and results fromto result from: wynikać z tiny hair fibresfibre: włókno, korzonek nerwowy in the inner earucho wewnętrzne detecting the motionruch, poruszanie się of atmospheric particlesparticle: cząsteczka, drobina within (at best) a rangezakres of 20 to 20000 Hz. Sound can also be detected as vibration by tactition. Lower and higher frequencies than can be heard are detected this way only.

Taste or gustation is one of the two "chemical" senses. It is well-known that there are at least four types of taste "bud" (receptor) on the tongue and hencedlatego, stąd, as should now be expected, there are anatomists who argue that these in fact constitute four or more different senses, given that each receptor conveysto convey: przekazywać, przenosić information to a slightly different region of the brain.

The four well-known receptors detect sweet, salt, sour, and bitter, although the receptors for sweet and bitter have not been conclusivelydecydująco, rozstrzygająco identified. A fifth receptor, for a sensationdoznanie, wrażenie called "umami", was first theorised in 1908 and its existence confirmed in 2000. The umami receptor detects the amino acid glutamateglutaminian aminokwasowy, a flavor commonly found in meat, and in artificial flavouringsflavouring: przyprawa such as monosodium glutamateglutaminian sodowy.

Smell or olfaction is the other "chemical" sense. Unlike taste, there are hundreds of olfactorywęchowy receptors, each binding toprzywiązany do, związany a particular molecular featurececha cząsteczkowa, molekularna, according to current theory. The combination of features of the odorzapach, woń molecule makes up what we perceive as the molecule's smell. In the brain, olfaction is processed by the olfactorywęchowy system. Olfactory receptor neurons in the nose differ from most other neurons in that they die and regenerate on a regular basisregularnie.

Note that in aquaticwodny, żyjący w wodzie organisms there is essentiallyistotnie, zasadniczo no difference between smell and taste.

The 2004 Nobel Prize in Physiology or Medicine (announced 4 October 2004) was won by Richard Axel and Linda Buck for their work explaining olfaction, published first in a joint paper in 1991 that described the very large family of about one thousand genes for odorantpachnący, aromatyczny receptors and how the receptors link to the brain.

The remaining senses can be considered types of touch or physical feeling.

Tactition is the sense of pressure perceptionpostrzeganie, generally in the skin.

Thermoception is the sense of heat and the absence of heat (cold), also by the skin and including internalwewnętrzny skin passagespassage: kanał, fragment. It is also the first of the group of senses not identified explicitlywyrażnie by Aristotle. Again there is some disagreement about how many senses this actually represents--the thermoceptors in the skin are quite different from the homeostatic thermoceptors which provide feedbackreakcja on internalwewnętrzny body temperature. How warm or cold something feels does not only depend on temperature, but also on specific heat capacitypojemność cieplna and heat conductanceprzewodnictwo cieplne; e.g., warm metal feels warmer than warm wood, and cold metal feels colder than cold wood, because metal has a higher thermal conductivityprzewodnictwo than wood. Wind feels cold because of the heat withdrawn for evaporationwyparowanie, wydzielanie of sweatpot or other moisturewilgoć, and because an isolating layer of warm air around the body blows awayto blow away: wywiewać; however, in the case of hot air, wind makes it feel hotter, for a similar reason as the latter.

Nociception is the perceptionpostrzeganie of pain. It can be classified as from one to three senses, depending on the classification method. The three types of pain receptors are cutaneousskórny (skin), somaticsomatyczny (jointsjoint: staw and bones) and visceralwewnętrzny (body organs).

Equilibrioception is the perceptionpostrzeganie of balance and is related to cavitiescavity: dziura, zagłębienie, jama containing fluid in the inner earucho wewnętrzne. There is some disagreement as to whether or not this also includes the sense of "direction" or orientation. However, as with depthgłębia perceptionpostrzeganie earlier, it is generally regarded that "direction" is a post-sensory cognitive awarenessświadomość.

Proprioception is the perceptionpostrzeganie of body awarenessświadomość and is a sense that people rely on enormouslyogromnie, gigantycznie, yet are frequently not aware of. More easily demonstrated than explained, proprioception is the "unconsciouspodświadomy" awarenessświadomość of where the various regions of the body are located at any one timekiedykolwiek. (This can be demonstrated by anyone closing their eyes and waving their hand around. Assuming properwłaściwy, odpowiedni proprioceptiveodbierający bodźce function, at no timenigdy will the person lose awarenessświadomość of where the hand actually is, even though it is not being detected by any of the other senses).

Based on this outlineszkic, zarys and depending on the chosen method of classification, somewhere between 9 and 21 human senses have been identified. Additionally, there are some other candidate physiological experiences which may or may not fall within the above classification (for example the sensory awarenessświadomość of hunger and thirst).

Non-human senses

All animals have receptors to sense the world around them, including many of the senses listed above for humans. However, the mechanisms and capabilities vary widely. Dogs have a much keenerkeen: wyostrzony sense of smell than humans, although the mechanism is similar. Moths have olfactorywęchowy receptors on their antennaeczułek and sound receptors on their wings. Ctenophores have a balance receptor (a statocyststatocysta) that works very differently from the mammalianodnoszący się do ssaka, ssący semi-circularpółkolisty canals. In addition, some animals have senses that humans do not, including the following:

Electroception (or "electroreception"), the most significant of the non-human senses, is the ability to detectwykrywać, wyczuwać electric fieldselectric field: pole elektryczne. Several species of fish, sharks and rayspromienie, promieniowanie have evolvedto evolve: rozwijać, ewoluować, przekształcać się the capacity to sense changes in electric fieldselectric field: pole elektryczne in their immediate vicinitybliskość, pobliże, sąsiedztwo. Some fish passivelybiernie, pasywnie sense changing nearby electric fieldselectric field: pole elektryczne, some generate their own weak, electric fieldselectric field: pole elektryczne and sense the pattern of field potentials over their body surface, and some use these generating and sensing capacities for social communication. The mechanisms by which electroceptive fishes construct a spatialprzestrzenny representation from very small differences in field potentials involve comparisons of spikekrótki impuls elektryczny latencieslatency: stan utajenia, utajenie from different parts of the fish's body.

The only mammal which is known to demonstrate electroception is the platypusdziobak.

Humans (and probably other mammals) can detect electric fieldselectric field: pole elektryczne indirectly by detecting the effect they have on hairs. An electrically charged balloon, for instance, will exertwpływać, wywierać nacisk a forcesiła on human arm hairs, which can be felt through tactition and identified as coming from a static chargenieruchomy, statyczny ładunek elektryczny (and not from wind or the like).

Magnetoception (or "magnetoreception") is the ability to detectwykrywać, wyczuwać fluctuationsfluctuation: wahanie, zmiana in magnetic fields and is most commonly observed in birds. Although there is no dispute that this sense exists in many aviansavian: ptasi (it is essential to the navigational abilities of migratorywędrowny birds) it is not a well understood phenomenon.

Magnetotactic bacteria build miniature magnetsmagnet: magnes inside themselves and use them to determine their orientation relative toodnoszący się do the Earth's magnetic fieldpole magnetyczne.

Echolocation is the ability to determine orientation to other objects through interpretation of reflected soundodbity dźwięk (like sonar). Bats and dolphins are notedto note: zapisywać, zauważać for this ability, though some other mammals and birds do as well. It is most often used to navigate through poor lighting conditions or to identify and tracktropić, śledzić preyofiara. There is presently an uncertainty as to whether this is simply an extremely developed post-sensory interpretation of auditorysłuchowy perceptions, or actually constitutesto constitute: tworzyć, stanowić, składać się na a separate sense. Resolution of the issue will require brain scans of animals while they actually perform echolocation, a task which has proved difficult in practice.

Pit vipers and some boas have organs that allow them to detectwykrywać, wyczuwać infrared lightpromieniowanie podczerwone, such that these snakes are able to sense the body heat of their preyofiara. This sense is in addition to and distinctróżny, odrębny from normal vision.

Url źródłowy: http://en.wikipedia.org/wiki/Senses

Słowniczek