AskDefine | Define touch

Dictionary Definition

touch

Noun

1 the event of something coming in contact with the body; "he longed for the touch of her hand"; "the cooling touch of the night air" [syn: touching]
2 the faculty of touch; "only sight and touch enable us to locate objects in the space around us" [syn: sense of touch, skin senses, touch modality, cutaneous senses]
3 a suggestion of some quality; "there was a touch of sarcasm in his tone"; "he detected a ghost of a smile on her face" [syn: trace, ghost]
4 a distinguishing style; "this room needs a woman's touch" [syn: signature]
5 the act of putting two things together with no space between them; "at his touch the room filled with lights" [syn: touching]
6 a slight but appreciable addition; "this dish could use a touch of garlic" [syn: hint, tinge, mite, pinch, jot, speck, soupcon]
7 a communicative interaction; "the pilot made contact with the base"; "he got in touch with his colleagues" [syn: contact]
8 a slight attack of illness; "he has a touch of rheumatism" [syn: spot]
9 the act of soliciting money (as a gift or loan); "he watched the beggar trying to make a touch"
10 the sensation produced by pressure receptors in the skin; "she likes the touch of silk on her skin"; "the surface had a greasy feeling" [syn: touch sensation, tactual sensation, tactile sensation, feeling]
11 deftness in handling matters; "he has a master's touch"
12 the feel of mechanical action; "this piano has a wonderful touch"

Verb

1 make physical contact with, come in contact with; "Touch the stone for good luck"; "She never touched her husband"
2 perceive via the tactile sense; "Helen Keller felt the physical world by touching people and objects around her"
3 affect emotionally; "A stirring movie"; "I was touched by your kind letter of sympathy" [syn: stir]
4 have to do with or be relevant to; "There were lots of questions referring to her talk"; "My remark pertained to your earlier comments" [syn: refer, pertain, relate, concern, come to, bear on, touch on]
5 be in direct physical contact with; make contact; "The two buildings touch"; "Their hands touched"; "The wire must not contact the metal cover"; "The surfaces contact at this point" [syn: adjoin, meet, contact]
6 have an effect upon; "Will the new rules affect me?" [syn: affect, impact, bear upon, bear on, touch on]
7 deal with; usually used with a form of negation; "I wouldn't touch her with a ten-foot pole"; "The local Mafia won't touch gambling"
8 cause to be in brief contact with; "He touched his toes to the horse's flanks"
9 to extend as far as; "The sunlight reached the wall"; "Can he reach?" "The chair must not touch the wall" [syn: reach, extend to]
10 be equal to in quality or ability; "Nothing can rival cotton for durability"; "Your performance doesn't even touch that of your colleagues"; "Her persistence and ambition only matches that of her parents" [syn: equal, rival, match]
11 tamper with; "Don't touch my CDs!" [syn: disturb]
12 make a more or less disguised reference to; "He alluded to the problem but did not mention it" [syn: allude, advert]
13 comprehend; "He could not touch the meaning of the poem"
14 consume; "She didn't touch her food all night" [syn: partake]
15 dye with a color [syn: tint, tinct, bepaint, tinge]

User Contributed Dictionary

English

Etymology

From Old French tochier (modern toucher), from Vulgar Latin toccare "to knock, strike", probably of imitative origin.

Pronunciation

  • /tʌʧ/
  • /tVtS/
  • Rhymes: -ʌtʃ

Verb

  1. To make physical contact with; to bring the hand, finger or other part of the body into contact with.
    I touched her face softly.
  2. To come into (involuntary) contact with; to meet or intersect.
    Sitting on the bench, the hem of her skirt touched the ground.
  3. To come into physical contact, or to be in physical contact.
    They stood next to each other, their shoulders touching.
  4. To make physical contact with a thing.
    Please can I have a look, if I promise not to touch?
  5. To physically affect in specific ways implied by context.
    Frankly, this wood's so strong that sandpaper won't touch it.
  6. To physically disturb; to interfere with, molest, or attempt to harm through contact.
    If you touch her, I'll kill you.
  7. To consume, or otherwise use.
    Are you all right? You've hardly touched your lunch.
  8. In the context of "transitive|dated": To affect in a negative way, especially only slightly.
    He had been drinking over lunch, and was clearly touched.
  9. To steal, or obtain money; to borrow money from.
    I was running short, so I touched old Bertie for a fiver.
  10. To affect emotionally; to bring about tender or painful feelings in.
    Stefan was touched by the song's message of hope.
  11. To concern, to have a bearing on.
    Stay out of this, it doesn't touch you in any way.
  12. To imbue or endow with a specific quality.
    My grandfather, as many people know, was touched with greatness.
  13. To disturb the mental functions of; to make somewhat insane.
    You must be touched if you think I'm taking your advice.
  14. (transitive or reflexive) To sexually excite with the fingers; to finger or masturbate.
    Her parents had caught her touching herself when she was fifteen.
  15. (transitive, Scottish history) To give royal assent to by touching it with the sceptre.
    The bill was finally touched after many hours of deliberation.
make physical contact with
affect emotionally

Noun

  1. An act of touching, especially with the hand or finger.
    Suddenly, in the crowd, I felt a touch at my shoulder.
  2. The faculty or sense of perception by physical contact.
    With the lights out, she had to rely on touch to find her desk.
  3. The style or technique with which one plays a musical instrument.
    He performed one of Ravel's piano concertos with a wonderfully light and playful touch.
  4. A distinguishing feature or characteristic.
    Clever touches like this are what make her such a brilliant writer.
  5. A little bit; a small amount.
    Move it left just a touch and it will be perfect.
  6. The part of a sports field beyond the touchlines or goal-lines.
    He got the ball, and kicked it straight out into touch.
  7. A relationship of close communication or understanding.
    He promised to keep in touch while he was away.
act of touching
sense of perception
  • Czech: hmat
  • Finnish: tuntoaisti, tunto
  • Greek: αφή (afí)
  • Japanese: 触覚
  • Polish: dotyk
  • Portuguese: toque
  • Russian: осязание
  • Swedish: känsel
style
distinguishing feature
small amount
part of a sportsfield
close communication
  • Finnish: yhteys, kontakti
  • Polish: kontakt
  • Portuguese: contato
  • Russian: общение, контакт
  • Swedish: kontakt

Extensive Definition

The somatosensory system is a widespread and diverse sensory system comprising of the receptors and processing centres to produce the sensory modalities touch, temperature, proprioception (body position), and nociception (pain). The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, and the cardiovascular system. While touch is considered one of the five traditional senses the impression of touch is formed from several modalities; In medicine, the colloquial term touch is usually replaced with somatic senses to better reflect the variety of mechanisms involved.
The system reacts to diverse stimuli using different receptors: thermoreceptors, mechanoreceptors and chemoreceptors. Transmission of information from the receptors passes via sensory nerves through tracts in the spinal cord and into the brain. Processing primarily occurs in the primary somatosensory area in the parietal lobe of the cerebral cortex.
At its simplest, the system works when a sensory neurone is triggered by a specific stimulus such as heat; this neurone passes to an area in the brain uniquely attributed to that area on the body - this allows the processed stimulus to be felt at the correct location. The mapping of the body surfaces in the brain is called a homunculus and is essential in the creation of body image.

Anatomy

The somatosensory system is spread through all major parts of a mammal's body (and other vertebrates). It consists both of sensory receptors and sensory (afferent) neurones in the periphery (skin, muscle and organs for example), and further neurones within the central nervous system.

General somatosensory pathway

A somatosensory pathway typically has three long neurons: primary, secondary and tertiary (or first, second, and third).

Periphery

In the periphery, the somatosensory system detects various stimuli by sensory receptors, e.g. by mechanoreceptors. The sensory information (touch, pain, temperature etc.,) is then conveyed to the central nervous system by afferent neurones. There are a number of different types of afferent neurones which vary in their size, structure and properties. Generally there is a correlation between the type of sensory modality detected and the type of afferent neurone involved. So for example slow, thin unmyelinated neurones conduct touch whereas faster, thicker, myelinated neurones conduct pain.

Spinal cord

In the spinal cord, the somatosensory system includes ascending pathways from the body to the brain. One major target within the brain is the postcentral gyrus in the cerebral cortex. This is the target for neurones of the Dorsal Column Medial Lemniscal pathway and the Ventral Spinothalamic pathway. Note that many ascending somatosensory pathways include synapses in either the thalamus or the reticular formation before they reach the cortex. Other ascending pathways, particularly those involved with control of posture project to the cerebellum. These include the ventral and dorsal spinocerebellar tracts. Another important target for afferent somatosensory neurones which enter the spinal cord are those neurones involved with local segmental reflexes.

Brain

The primary somatosensory area in the human cortex is located in the postcentral gyrus of the parietal lobe. The postcentral gyrus is the location of the primary somatosensory area, the main sensory receptive area for the sense of touch. Like other sensory areas, there is a map of sensory space called a homunculus in this location. For the primary somatosensory cortex, this is called the sensory homunculus. Areas of this part of the human brain map to certain areas of the body, dependent on the amount or importance of somatosensory input from that area. For example, there is a large area of cortex devoted to sensation in the hands, while the back has a much smaller area. Interestingly, one study showed somatosensory cortex was found to be 21% thicker in 24 migraine sufferers, on average than in 12 controls, although we do not yet know what the significance of this is. Somatosensory information involved with proprioception and posture also targets an entirely different part of the brain, the cerebellum.

Physiology

Initiation of probably all "somatosensation" begins with activation of some sort of physical "receptor". These somatosensory receptors, tend to lie in skin, organs or muscle. The structure of these receptors is broadly similar in all cases, consisting of either a "free nerve ending" or a nerve ending embedded in a specialised capsule. They can be activated by movement (mechanoreceptor), pressure (mechanoreceptor), chemical (chemoreceptor) and/or temperature. In each case, the general principle of activation is similar; the stimulus causes depolarisation of the nerve ending and an action potential is inititated. This action potential then (usually) travels inward towards the spinal cord.

Technology

The new research area of haptic technology allows to provide touch sensation in virtual and real environments. This exciting new area has started to provide critical insights into touch capabilities.

Notes

References

  • Medical Physiology
touch in Min Nan: Thé-kak hē-thóng
touch in Spanish: Sistema somatosensorial
touch in Esperanto: Tuŝa sistemo
touch in French: Somesthésie
touch in Hebrew: מערכת המגע
touch in Indonesian: Sistem somatosensori
touch in Icelandic: Líkamsvitund
touch in Japanese: 体性感覚
touch in Portuguese: Sistema somatosensorial
touch in Russian: Соматосенсорная система
touch in Swedish: Beröring
touch in Võro: Pututaminõ
touch in Chinese: 体感

Synonyms, Antonyms and Related Words

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converse, correspond, correspond to, correspondence, cover, dab, dash, deal with, dealing, dealings, decorative composition, decorative style, deftness, demilegato, design, detail, detonate, dexterity, dip, disturb, ditto, draw, drink, drop, eat, employ, enhance, equal, even, even off, examine, exchange, exchange colors, excite, execution, experience, expertise, expression, facility, feel, feel of, feeling, figure, fillip, finger, fingering, fire, five senses, flag, flag down, flair, flare, flash, flick, flip, flirt, float a loan, fog bell, fog signal, fog whistle, foghorn, foil, foment, fondle, foreground detail, form, genius, get, get a loan, get on credit, get to, gift, give a signal, give rise to, give the nod, glance, gleam, glissando, go deep, go light, go through one, gong buoy, graze, green light, grieve, hail, hail and speak, half-mast, hand, handle, hang, have connection with, hear, hearing, heliograph, high sign, hint, hit, hit one for, hit up, hoist a banner, idea, ignite, impassion, impinge, impingement, impingence, implication, implied meaning, import, impress, inference, influence, information, infusion, initiate, inkling, innuendo, inspect, inspire, instigate, interaction, interchange, intercommunication, intercommunion, intercourse, interest, interfere with, international alphabet flag, international numeral pennant, interplay, intimation, intonation, investigate, involve, ironic suggestion, join, jot, junction, keep pace with, kick, kiss, knack, knot, land, larceny, leer, legato, liaise with, lick, lift, light, line, linguistic intercourse, link with, look, make a sign, make use of, manner, march, marker beacon, match, match up with, meaning, measure up, measure up to, meddle with, meet, melt, melt the heart, mention, message, metaphorical sense, method, mezzo staccato, mooch, motif, move, movement, music-making, national style, negotiate a loan, neighbor, nod, nuance, nudge, occult meaning, odor, operation, ornamental motif, osculate, osculation, overtone, palm, palpate, palpation, panhandle, parachute flare, parallel, parlando, partake of, pass the hat, pat, patch up, pattern, paw, pawn, peck, penetrate, perceive, performance, period style, pertain to, phonism, photism, pianism, pick, pierce, pilot flag, pinch, pizzicato, ply, poke, poke at, police whistle, presumption, presupposition, probe, prod, provoke, purloining, put, put to use, quarantine flag, quicken, radio beacon, raise, raise a cry, raise money, rap, reach, receptor, red flag, red light, refer to, regard, relate to, rendering, rendition, renovate, repeated figure, repercussion, reply, respect, respond, respond to stimuli, response, responsiveness, retouch, rival, rocket, rub, rubato, run abreast, run into debt, run to, sadden, sailing aid, salute, sauce, scent, scintilla, scrape, scrounge, scrutinize, seasoning, see, semaphore, semaphore flag, semaphore telegraph, sense, sense organ, senses, sensillum, sensorium, sensory organ, set, set in motion, set off, setting, shade, shadow, shave, sideswipe, sight, sign, signal, signal beacon, signal bell, signal fire, signal flag, signal gong, signal gun, signal lamp, signal light, signal mast, signal post, signal rocket, signal shot, signal siren, signal tower, signalize, signature, sip, sixth sense, skill, skim, skirt, slur, smack, smart, smattering, smell, snap, social intercourse, soften, sound an alarm, sound the trumpet, soupcon, spar buoy, spark, speak, speaking, speck, speech, speech circuit, speech situation, spiccato, spice, spot, sprinkling, spruce up, squeak by, staccato, stack up with, start, steal, stealage, stealing, stimulate, sting, stir, stop light, streak, strike, stroke, style, subsense, subsidiary sense, suggestion, sup, supposition, suspicion, sway, symbolism, synesthesia, tactility, taction, taint, take, take advantage of, talent, talking, tangency, tap, taste, technique, telepathy, tempering, tentative contact, texture, the nod, the wink, theme, thievery, thieving, thought, thumb, tickle, tie, tie in with, tinct, tincture, tinge, tint, tip, titivate, touch a chord, touch down, touch off, touch on, touch up, touch upon, touching, toy with, trace, traffic, traffic light, traffic signal, treat of, trick, trigger, truck, twiddle, two-way communication, undercurrent, undermeaning, undertone, unfurl a flag, use, verge, verge on, vestige, watch fire, wave, wave a flag, wave the hand, way, whiff, whisk, white flag, wield, wigwag, wigwag flag, wink, yellow flag
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