Electro-physiology (1896-98) Electro-physiology electrophysiolog01bied Year: 1896-98 II CHANGE OF FORM IN MUSCLE DURING ACTIVITY 117 The significance of twitch helps the first, pretty much according to Helmholtz's law, while in the case where the second contraction rises from the summit of the first, the height of the summated contraction is always less than would correspond with the rule. We have already considered the effect, where, on repeated excitation with equal, maximal, induction currents, the height of twitch grows in the form of a ' staircase.' this fact to the consequences of summa
Electro-physiology (1896-98) Electro-physiology electrophysiolog01bied Year: 1896-98 II CHANGE OF FORM IN MUSCLE DURING ACTIVITY 117 The significance of twitch helps the first, pretty much according to Helmholtz's law, while in the case where the second contraction rises from the summit of the first, the height of the summated contraction is always less than would correspond with the rule. We have already considered the effect, where, on repeated excitation with equal, maximal, induction currents, the height of twitch grows in the form of a ' staircase.' this fact to the consequences of summation has been pointed out by Ch. Eichet (4) in particular. He chiefly investigated the striated muscle of crab, in which the increase of excitability with repeated and uniform stimuli is very marked. Even in the case in which the single stimuli individually excite only sub - maximal twitches, and exhil lit hardly any perceptible change of form (are ' subliminal'), they may, on repeated application, become effec- tive, because each single excitation increases the muscular response to the next Stimulus (addition F,G 49__ ^ Addition tatente'; muscle of Crab ;increas- latente). Kg. 49 demon- strates very forcibly this effect of repeated uniform stimuli, each per -sr ineffective, upon the muscle. The two first stimuli had no perceptible action, the third stimulus produces a minimal contraction, the fourth, one some- what greater, while the three subsequent stimuli produce very marked contractions, which are fused into an incomplete tetanus. It is clear that such a dependence of excitability upon a previous excitation must sensibly affect the height of a summated twitch, as well as the magnitude of the tetanus shortening. And thus ing effect of seven consecutive single stimuli (induc- tion shocks), each ineffective per se. (Ch. Richet.)
Size: 1138px × 1758px
Photo credit: © Bookworm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
