1. A shortening or increase in tension; denoting the normal function of muscle. 2. A shrinkage or reduction in size. 3. Heart beat, as in premature c..beat. [L. contractus, drawn together]
- after-c. aftercontraction.
- anodal closure c. (ACC, AnCC) obsolete term for the momentary c. of a muscle under the influence of the positive pole when the electrical circuit is established.
- anodal opening c. (AnOC, AOC) obsolete term for the momentary c. of a muscle under the influence of the positive pole when the circuit is broken.
- automatic c. SYN: automatic beat.
- Braxton Hicks c. rhythmic myometrial activity occurring during the course of a pregnancy that usually causes no pain for the patient.
- cathodal closure c. (CaCC, CCC) obsolete term for the momentary c. of a muscle under the influence of the negative pole when an electrical circuit is established.
- cathodal opening c. (CaOC, COC) obsolete term for the momentary c. of a muscle under the influence of the negative pole when the circuit is broken.
- closing c. c. produced at the time of closing of the circuit when using direct current to stimulate the muscle.
- escape c. SYN: escape beat.
- escape ventricular c. an escape beat arising in the ventricle.
- fibrillary contractions contractions occurring spontaneously in individual muscle fibers; they are seen commonly a few days after damage to the motor nerves supplying the muscle, and this type of activity is distinguished from fasciculation, which is related to activation of motor units.
- front-tap c. c. of the calf muscles when the anterior surface of the leg is struck. SYN: Gowers c..
- Gowers c. SYN: front-tap c..
- hourglass c. constriction of the middle portion of a hollow organ, such as the stomach or the gravid uterus.
- hunger contractions strong contractions of the stomach associated with hunger pains.
- isometric c. force development at constant length. Cf.:isotonic c..
- isotonic c. shortening at constant force development. Cf.:isometric c.. SYN: isotonic exercise.
- myotatic c. a reflex c. of a skeletal muscle that occurs as a result of stimulation of the stretch receptors in the muscle, i.e., as part of a myotatic reflex.
- opening c. a c. produced at the time of opening the circuit when using direct current to stimulate the muscle or a motor nerve.
- paradoxical c. a tonic c. of the anterior tibial muscles when a sudden passive dorsal flexion of the foot is made.
- postural c. maintenance of muscular tension (usually isometric) sufficient to maintain posture.
- reflex detrusor c. normal coordinated function of the bladder with sustained contractions of the bladder matched by simultaneous relaxation of the sphincteric outlet mechanisms to empty the bladder.
- tetanic c. tetanus (2).
- tonic c. sustained c. of a muscle, as employed in the maintenance of posture.
- uterine c. rhythmic activity of the myometrium associated with menstruation, pregnancy, or labor.

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con·trac·tion kən-'trak-shən n
1) the action or process of contracting: the state of being contracted <\contraction of hepatitis> <lung expansion and \contraction in breathing (P. G. Donohue)>
2) the action of a functioning muscle or muscle fiber in which force is generated accompanied esp. by shortening and thickening of the muscle or muscle fiber or sometimes by its lengthening <isometric \contraction> <isotonic \contraction> esp the shortening and thickening of a functioning muscle or muscle fiber
3) one of usu. a series of rhythmic tightening actions of the uterine muscles (as during menstruation or labor)

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the shortening of a muscle in response to a motor nerve impulse. This generates tension in the muscle, usually causing movement.

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con·trac·tion (kən-trakґshən) [L. contractus drawn together] 1. a reduction in size or shrinkage. 2. in muscle, an increase in tension that may or may not shorten the muscle. 3. abnormal approximation of mandibular and maxillary structures to the median plane. See also distraction (def. 5).

Medical dictionary. 2011.

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  • contraction — [ kɔ̃traksjɔ̃ ] n. f. • XVe; contraicion 1256; lat. contractio, de contrahere → 2. contracter 1 ♦ Vx Diminution du volume d un corps, sans modification de sa masse. Contraction par le froid, la pression. ♢ Mod. Physiol. Diminution de volume ou de …   Encyclopédie Universelle

  • Contraction — may refer to: In physiology: Muscle contraction, one that occurs when a muscle fiber lengthens or shortens Uterine contraction, contraction of the uterus, such as during childbirth Contraction, a stage in wound healing In linguistics: Synalepha,… …   Wikipedia

  • contraction — CONTRACTION. s. f. Terme de Physique, qui se dit Du raccourcissement qui arrive aux nerfs ou aux muscles lorsqu ils viennent à se etirer. La systole du coeur consiste dans sa contraction. Contraction volontaire, contraction involontaire des… …   Dictionnaire de l'Académie Française 1798

  • Contraction — Con*trac tion, n. [L. contractio: cf. F. contraction.] 1. The act or process of contracting, shortening, or shrinking; the state of being contracted; as, contraction of the heart, of the pupil of the eye, or of a tendon; the contraction produced… …   The Collaborative International Dictionary of English

  • contraction — CONTRACTION. s. f. Racourcissement des nerfs, des muscles, qui sont retirez. Une grande contraction de nerfs. cette fluxion, cette blessure luy causa la contraction d un tel muscle. Il est aussi usité en Grammaire, où il signifie la reduction de… …   Dictionnaire de l'Académie française

  • contraction — late 14c., action of making a contract (especially of marriage), also action of shrinking or shortening, from O.Fr. contraction (13c.), or directly from L. contractionem (nom. contractio), noun of action from pp. stem of contrahere (see CONTRACT… …   Etymology dictionary

  • contraction — [kən trak′shən] n. [ME contraccioun < OFr contraction < L contractio] 1. a contracting or being contracted 2. the shortening and thickening of a muscle fiber or a muscle in action, esp. of the uterus during labor 3. Gram. a) the shortening… …   English World dictionary

  • Contraction — Contraction. См. Усадка. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Contraction — (v. lat.), 1) das Zusammenziehen nachgiebiger Theile, vermöge der ihnen eigenthümlichen Contractibilität; Gegensatz: Expansion; 2) (Gramm.), Zusammenziehung zweier od. mehrerer, besonders auszusprechender Vocale desselben Wortes in Einen Laut,… …   Pierer's Universal-Lexikon

  • contraction — index abridgment (condensation), abstract, blockade (limitation), compendium, curtailment, decline …   Law dictionary

  • contraction — [n] drawing in; shortening abbreviating, abbreviation, abridging, abridgment, compression, condensation, condensing, confinement, confining, constriction, curtailing, curtailment, cutting down, decrease, decreasing, deflating, deflation,… …   New thesaurus

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