WordNet
- (physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber) (同)muscular_contraction, muscle_contraction
- the act of decreasing (something) in size or volume or quantity or scope
- a word formed from two or more words by omitting or combining some sounds; "`wont is a contraction of `will not"; "`oclock is a contraction of `of the clock"
- relating to or characterized by the equal intervals of a musical scale; "isotonic tuning"
- (used of solutions) having the same or equal osmotic pressure (同)isosmotic
- of or involving muscular contraction in which tension is constant while length changes
- of two or more muscles; having equal tension
PrepTutorEJDIC
- 〈U〉〈C〉(…の)収縮,短縮《+『of』+『名』》 / 〈U〉(通貨・資金・支出などの)縮小,節減《+『of』+『名』》 / 〈U〉(いやなこと・よくないことを)身に負うこと,(悪習などが)身につくこと《+『of』+『名』》 / 〈C〉陣痛
- 等張の(2種の容液の浸透圧が等しい)
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出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/09/08 22:04:42」(JST)
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In an isotonic contraction, tension remains unchanged and the muscle's length changes. Isotonic contractions differ from isokinetic contractions in that in isokinetic contractions the muscle speed remains constant. While superficially identical, as the muscle's force changes via the length-tension relationship during a contraction, an isotonic contraction will keep force constant while velocity changes, but an isokinetic contraction will keep velocity constant while force changes. A near isotonic contraction is known as Auxotonic contraction.
There are two types of isotonic contractions: (1) concentric and (2) eccentric. In a concentric contraction, the muscle tension rises to meet the resistance, then remains the same as the muscle shortens. In eccentric, the muscle lengthens due to the resistance being greater than the force the muscle is producing.
Contents
- 1 Concentric
- 2 Eccentric
- 3 Auxotonic contraction
- 4 See also
- 5 External links
Concentric
This type is typical of most exercise. The external force on the muscle is less than the force the muscle is generating - a shortening contraction. The effect is not visible during the classic biceps curl, which is in fact auxotonic because the resistance (torque due to the weight being lifted) does not remain the same through the exercise. Tension is highest at a parallel to the floor level, and eases off above and below this point. Therefore tension changes as well as muscle length.
Eccentric
There are two main features to note regarding eccentric contractions. First, the absolute tensions achieved can be very high relative to the muscle's maximum tetanic tension generating capacity (you can set down a much heavier object than you can lift[citation needed]). Second, the absolute tension is relatively independent of lengthening velocity. This suggests that skeletal muscles are very resistant to lengthening, thereby allowing very high levels of tension to develop as can occur in isometric exercise.
Muscle injury and soreness are selectively associated with eccentric contraction (Fridén et al. 1984; Evans et al. 1985; Fridén and Lieber, 1992). However, muscle strengthening may be greatest using exercises that involve eccentric contractions because high levels of tension generate the signals for muscle strengthening.
Auxotonic contraction
This is almost an isotonic contraction because there is some fluctuation towards the end of the contraction. For example, the heart's ventricles contract to expel blood into the pulmonary artery and aorta. As the blood flows out, the previous built-up load is decreased and hence less force is required to expel the rest of the blood. Thus the tension is reduced.
See also
- Isometric exercise (contraction, no movement)
- Stretching (passive, no contraction)
External links
- Isotonic contraction at the US National Library of Medicine Medical Subject Headings (MeSH)
Physiology of muscles
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Exertion |
- Exercise
- Movement
- Eye movement
- Gait
- Locomotion
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Other |
- Hand strength
- Muscle tone
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- Muscle contraction
- Isometric
- Isotonic
- Uterine contraction
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Index of muscle
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Description |
- Anatomy
- head
- neck
- arms
- chest and back
- diaphragm
- abdomen
- genital area
- legs
- Muscle tissue
- Physiology
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Disease |
- Myopathy
- Soft tissue
- Connective tissue
- Congenital
- abdomen
- muscular dystrophy
- Neoplasms and cancer
- Injury
- Symptoms and signs
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Treatment |
- Procedures
- Drugs
- anti-inflammatory
- muscle relaxants
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UpToDate Contents
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English Journal
- Lymph flow pattern in pleural diaphragmatic lymphatics during intrinsic and extrinsic isotonic contraction.
- Moriondo A1, Solari E1, Marcozzi C1, Negrini D2.
- American journal of physiology. Heart and circulatory physiology.Am J Physiol Heart Circ Physiol.2016 Jan 1;310(1):H60-70. doi: 10.1152/ajpheart.00640.2015. Epub 2015 Oct 30.
- Peripheral rat diaphragmatic lymphatic vessels, endowed with intrinsic spontaneous contractility, were in vivo filled with fluorescent dextrans and microspheres and subsequently studied ex vivo in excised diaphragmatic samples. Changes in diameter and lymph velocity were detected, in a vessel segmen
- PMID 26519032
- Contribution of elastic tissues to the mechanics and energetics of muscle function during movement.
- Roberts TJ1.
- The Journal of experimental biology.J Exp Biol.2016 Jan;219(Pt 2):266-75. doi: 10.1242/jeb.124446.
- Muscle force production occurs within an environment of tissues that exhibit spring-like behavior, and this elasticity is a critical determinant of muscle performance during locomotion. Muscle force and power output both depend on the speed of contraction, as described by the isotonic force-velocity
- PMID 26792339
- Isolation and evaluation of the myorelaxant effect of bergapten on isolated rat jejunum.
- Skalicka-Woźniak K1, Mendel M2, Chłopecka M2, Dziekan N2.
- Pharmaceutical biology.Pharm Biol.2016 Jan;54(1):48-54. doi: 10.3109/13880209.2015.1014570. Epub 2015 Apr 17.
- CONTEXT: Plants of the genus Heracleum L. (Apiaceae) have a long history of being used in traditional medicines for the treatment of alimentary tract disorders, and these biological effects have been ascribed to the presence of furanocoumarins (including bergapten).OBJECTIVES: This study aimed to de
- PMID 25885935
Japanese Journal
- Theory of muscle contraction mechanism with -cooperative interaction among crossbridges
- Mitsui Toshio,Ohshima Hiroyuki
- BIOPHYSICS 8(0), 27-39, 2012
- … The power stroke model was criticized and a model was proposed for muscle contraction mechanism (Mitsui, 1999). …
- NAID 130002061598
- Two Tendon-Driven Systems Using Pneumatic Balloons
- NAGASE Jun-ya,SAGA Norihiko
- Advanced robotics : the international journal of the Robotics Society of Japan 25(9), 1349-1361, 2011-06-01
- NAID 10029513821
Related Links
- contraction [kon-trak´shun] a drawing together; a shortening or shrinkage. Braxton Hicks c's see braxton hicks contractions. carpopedal contraction the condition resulting from chronic shortening of the muscles of the upper and lower ...
- Isotonic and isometric contractions are changes that take place in your muscles when they move or come under some form of physical stress. Isotonic contraction occurs when your muscles change length ...
★リンクテーブル★
[★]
- 短縮、収縮。(筋肉の)収縮、攣縮。(医)(腎・肝・膀胱などの)萎縮
- 縮小。制限。(通貨・資金などの)制限、回収、縮小。不況
- (数)縮小、縮約。省略算。(文法)縮約、短縮
- 負債を作ること、病気にかかること、癖のつくこと
- 交わり/約束を結ぶこと(of)
[★]
- 等張の、等張性の、等圧の、アイソトニックな、等張力性の、緊張力性の
- 関
- isobar、isobaric、isosmotic、isotonicity