tonic contraction


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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 limbs including the fingers and toes, seen in tetany.
concentric contraction contraction resulting in shortening of a muscle, used to perform positive work or to accelerate a body part. It is metabolically more demanding than an eccentric contraction. Called also shortening contraction.
Dupuytren's contraction Dupuytren's contracture.
eccentric contraction contraction in the presence of a resistive force that results in elongation of a muscle, used to perform negative work or to decelerate a body part. It is less metabolically demanding than a concentric contraction but may cause disruption of associated connective tissue with delayed soreness or frank injury if it occurs in an unaccustomed manner. Called also lengthening contraction.
end-diastolic premature ventricular contraction a ventricular ectopic beat falling at the end of diastole; it may or may not be slightly premature and may or may not be a fusion beat.
haustral c's muscular contractions of the wall of the large intestine during which the haustra can be seen more easily; called also haustrations.
isometric contraction muscle contraction without appreciable shortening or change in distance between its origin and insertion.
isotonic contraction muscle contraction without appreciable change in the force of contraction; the distance between the origin and insertion becomes lessened.
lengthening contraction eccentric contraction.
postural contraction the state of muscular tension and contraction that just suffices to maintain the posture of the body.
segmental c's muscular contractions of the small intestine that serve to mix and transport chyme.
shortening contraction concentric contraction.
contraction stress test observation of the fetal heart rate in response to uterine contractions; see also fetal monitoring.
tetanic contraction (tonic contraction) physiological tetanus.
Volkmann's contraction Volkmann's contracture.

ton·ic con·trac·tion

sustained contraction of a muscle, as employed in the maintenance of posture.

tonic contraction

Tetanus Neurology Smooth muscle contraction of a muscle. Cf Muscle twitching.

ton·ic con·trac·tion

(ton'ik kŏn-trak'shŭn)
Sustained contraction of a muscle, as employed in the maintenance of posture.
References in periodicals archive ?
To analyze these force recordings, we evaluated a variety of characteristics: maximal force (Fmax), mean force during the first minute of stimulation (Fm1n), number of series of claps (Nps), number of tonic contractions (Ntc), number of claps per series of claps (Npc1, Npc2, Npc3 etc) mean force change per series of claps (Fpcm1, Fpcm2, Fpcm3 etc), clapping rate during each series (rpc1, rpc2, rpc3 etc), force change and duration of the tonic contractions (Ftc1, Ftc2, Ftc3, etc and Dtc1, Dtc2, Dtc3 etc, respectively), maximum number of claps per series (Npc max), mean clapping rate (rpcm) and total number of claps(Npctot).
An alternation between series of claps and individual tonic contractions was present in all the recordings examined (Fig.
The duration of tonic contractions increased as the escape response progressed (Fig.
4), the close positioning of the number of tonic contractions (Ntc) and the number of series of claps (Nps) reflected that series of claps are separated by tonic contractions.
The behavioral PCA did not yield a PC highlighting tonic contractions, rather the performance of the tonic and phasic contractions was closely intertwined in both PC.
Transient and tonic contractions induced by angiotensin II and phenylephrine in rat thoracic aortas under pressure overload.
Although the time resolution of the force gauge prevents in vivo measurements of certain characteristics, such as the time to peak force and time to relaxation, this method reliably demonstrated phasic and tonic contractions as well as changes in phasic and tonic force throughout escape response activity.
Also, silymarin failed to affect the amplitude of the tonic contractions induced by 1 [micro]M carbachol in CYP-injected rats (Table 1).
Euxanthone was added cumulatively during the tonic contractions induced by phenylephrine (3 [micro]M), and KCI (80 mM) in tissues previously suspended in normal Krebs-Henseleit solution with the following composition (mM): NaCl 110.8, KCl 5.9, NaH[CO.sub.3] 25.0, Mg[SO.sub.4] 1.07, Ca[Cl.sub.2] 2.49, Na[H.sub.2]P[O.sub.4] 2.33 and glucose 11.51.