What's the difference between contraction and depolarize?

Contraction


Definition:

  • (n.) 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 tendion; the contraction produced by cold.
  • (n.) The process of shortening an operation.
  • (n.) The act of incurring or becoming subject to, as liabilities, obligation, debts, etc.; the process of becoming subject to; as, the contraction of a disease.
  • (n.) Something contracted or abbreviated, as a word or phrase; -- as, plenipo for plenipotentiary; crim. con. for criminal conversation, etc.
  • (n.) The shortening of a word, or of two words, by the omission of a letter or letters, or by reducing two or more vowels or syllables to one; as, ne'er for never; can't for can not; don't for do not; it's for it is.
  • (n.) A marriage contract.

Example Sentences:

  • (1) During the performance of propulsive waves of the oesophagus the implanted vagus nerve caused clonic to tetanic contractions of the sternohyoid muscle, thus proving the oesophagomotor genesis of the reinnervating nerve fibres.
  • (2) But RWE admitted it had often only been able to retain customers with expired contracts by offering them new deals with more favourable conditions.
  • (3) Thus adrenaline, via pre- and post-junctional adrenoceptors, may contribute to enhanced vascular smooth muscle contraction, which most likely is sensitized by the elevated intracellular calcium concentration.
  • (4) Further, the maximal increase in force of contraction was measured using papillary muscle strips from some of these patients.
  • (5) When subjects centered themselves actively, or additionally, contracted trunk flexor or extensor muscles to predetermined levels of activity, no increase in trunk positioning accuracy was found.
  • (6) Twitch-tetanus ratios were calculated and found not to be related to unit contraction time.6.
  • (7) Selective removal of endothelium had no effect on BK-induced contraction or the action of the antagonists.
  • (8) The increased muscular strength in due to a rise of calcaemia, improved muscle contraction and probably also due to the mentioned nutritional factors.
  • (9) However, there was not a relationship between the contraction curve of the gallbladder and the bile flow into the duodenum.
  • (10) In in vitro preparations GABA (10(-7) - 10(-3) M) elicited a dose-dependent relaxation; a decrease in the spontaneous contractions was sometimes observed.
  • (11) There was no correlation between disturbed gastric clearance, impaired gall bladder contraction, and prolonged colonic transit time in the patients with cardiovascular autonomic neuropathy nor was there a correlation between any disturbed motor function and age or duration of diabetes.
  • (12) Noradrenaline decreased the phasic contraction amplitude of the circular muscle and exerted a stimulant effect on the tone which suggested an existence of two alpha 1-adrenoceptor subtypes.
  • (13) It may, however, be useful to compare local wall dynamics in the more isometrically-contracting basal segment with those in the middle portion which brings about most of the emptying of the ventricle.
  • (14) Upon depletion of ATP in contraction, the P2 intensity reverted to the original rigor level, accompanied by development of rigor tension.
  • (15) L-NAME abolished B contractions in a dose-dependent fashion.
  • (16) The power spectrum of the EMG was analyzed during isometric contractions of the shoulder muscles.
  • (17) A23187 had only a transient effect on KCl-contracted coronary arteries.
  • (18) When caffeine evokes a contraction, and only then, crayfish muscle fibers become refractory to a second challenge with caffeine for up to 20 min in the standard saline (5 mM K(o)).
  • (19) Dopamine at concentrations over 10(-5)M induced contractions of tracheal muscle strips and repeated exposures resulted in desensitization (tachyphylaxis) of the muscle.
  • (20) In the present study we examined cholecystokinin release and gallbladder contraction after oral administration of a commercial fatty meal (Sorbitract; Dagra, Diemen, The Netherlands) using ultrasonography in eight normal subjects and eight gallstone patients before and after 1 and 4 weeks of treatment with ursodeoxycholic acid (10 mg kg-1.day-1).

Depolarize


Definition:

  • (v. t.) To deprive of polarity; to reduce to an unpolarized condition.
  • (v. t.) To free from polarization, as the negative plate of the voltaic battery.

Example Sentences:

  • (1) These channels may, at least in some cases, be responsible for the generation of pacemaker depolarizations, thereby regulating firing behaviour.
  • (2) Such an increase in antibody binding occurred simultaneously with an increase in the fluidity of surface lipid regions, as monitored by fluorescence depolarization of 1-(trimethylammoniophenyl)-6-phenyl-1,3,5-hexatriene.
  • (3) In experiments performed to determine whether PtdIns(4,5)P2 hydrolysis induced by TRH may have been caused by the elevation of [Ca2+]i, the following results were obtained: the effect of TRH to decrease the level of PtdIns(4,5)P2 was not reproduced by the calcium ionophore A23187 or by membrane depolarization with 50 mM K+; the calcium antagonist TMB-8 did not inhibit the TRH-induced decrease in PtdIns(4,5)P2; and, most importantly, inhibition by EGTA of the elevation of [Ca2+]i did not inhibit the TRH-induced decrease in PtdIns(4,5)P2.
  • (4) In K+-depolarized basilar arteries, ifenprodil competitively antagonized the response to Ca2+, and this was enhanced by pre-incubation in calcium hopantenate.
  • (5) For dental procedures requiring tracheal intubation, one could perhaps use non-depolarizing muscle relaxants, like pancuronium, with reversal at the end of the procedure.
  • (6) Propranolol, 0.85 X 10(-6) M, did not significantly depress the ouabain-enhanced rate of phase 4 depolarization but did attenuate the response to epinephrine through beta blockade.
  • (7) The decrease in cardiac performance observed during ventricular pacing was related to the severity of asynchrony rather than the direction of the ventricular depolarization or change in regional myocardial tension.
  • (8) In the absence of external chloride changing the external potassium concentration from 2.8 mM to potassium-free caused a depolarization of the membrane of about 30 mV and a small increase in membrane resistance.
  • (9) Detailed voltage-clamp measurements revealed that ABA-activated ion currents could be reversed by depolarizations more positive than -10 mV.
  • (10) The analysis suggests that the wave-peak discharge results from synchronous alternation of depolarization potentials and long periods of postsynaptic inhibition in most of the cortical elements.
  • (11) Using the rate coefficient values found by SCoPfit, we simulated a voltage-clamp experiment with both models running under their Na(+)-Na+ exchange mode, and we computed the transient currents generated following voltage steps in both depolarizing and hyperpolarizing directions from a basic potential of -40 mV.
  • (12) Stepwise depolarizations from the holding potential (-67 to -83 mV) to a potential which varied from -10 to +63 mV resulted in an exponential decline of h from its initial level to a final, non-zero level.
  • (13) In the whole-cell current-clamp method, the cell membrane was depolarized by endothelin and then repolarized by nicorandil.
  • (14) Anthopleurin-A produced two distinct responses in crayfish giant axons: depolarization and prolongation of action potentials.
  • (15) Diltiazem also produced a slight decrease of both the steady-state current during depolarization and the tail current after repolarization in these concentration ranges, while the hyperpolarization activated current (Ih) was not affected significantly.
  • (16) Furthermore, it explains rapid termination of release after depolarization, even though Ca2+ concentration may still be high.
  • (17) Depolarizations induced by acetyl-Arg6-septide, a NK1-receptor selective agonist, were also antagonized by spantide with a pA2 of 6.5.
  • (18) This response seemed to be triggered mainly by the influx of Ca2+ through L-type Ca2+ channel activated by membrane depolarization, which was caused by the ATP-induced inward current.
  • (19) When the concentration of Ca2+ in the medium was raised to 10 mM was the only extracellular divalent cation present, the depolarization in response to A23187 was increased to 11-8 mV.
  • (20) Generally, more distant neurones (500-1300 microns) were excited for variable periods of time (3-15 min), while neurones in the vicinity of the injection site (0-500 microns) showed, after a brief period of excitation time, a long-lasting (up to 30 min) decrease in excitability or silencing of discharge, probably due to a depolarizing block and disturbances in the ionic composition of the extracellular space.