. Medical electricity; a practical treatise on the applications of electricity to medicine and surgery. fU-\ The muscle-nerve preparation of Fig. 55, and the clamp electrode, and electrode-holder are here shown on a larger scale—the letters as in Fig. 55. The form of elec-trode-holder figured is a convenient one for general purposes, but many other forms arein use. 104 ELECTRO-PHYSIOLOGY. arranged so that its movements can be recorded on a re-volving cylinder. The whole apparatus is represented inFig. 55 and Fig. 56 (from Fosters Physiology). A muscle-curve obtained by this apparatus has the f
. Medical electricity; a practical treatise on the applications of electricity to medicine and surgery. fU-\ The muscle-nerve preparation of Fig. 55, and the clamp electrode, and electrode-holder are here shown on a larger scale—the letters as in Fig. 55. The form of elec-trode-holder figured is a convenient one for general purposes, but many other forms arein use. 104 ELECTRO-PHYSIOLOGY. arranged so that its movements can be recorded on a re-volving cylinder. The whole apparatus is represented inFig. 55 and Fig. 56 (from Fosters Physiology). A muscle-curve obtained by this apparatus has the formshown in Fig. 57. We learn from this that a muscular. A muscle-curve, a indicates the moment when an induction-shock is sent into thenerve; b, the commencement; c, the maximum; and d, the close of the contraction.(Foster.) contraction, which seems a single movement, is made upof several. There is a distinct interval between the re-ception of the shock of the induction coil, and the begin-ning of the muscular contraction. This period, which isantecedent to any visible alteration in the muscle, is knownas the latent period. Then follows the phase of contrac-tion which is not instantaneous, but gradual, reaching itsmaximum, and then relaxing, the whole act occupyingabout one-twentieth of a second. When a descending galvanic current is made to traversea motor nerve, a contraction of the muscles to which thenerve is distributed takes place at .the closing and, undersome circumstances, at the opening or cessation of the,current. If there be no variations in the intensity of thecurrent, during the whole time it is passing, the musclesremain qui
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectro, bookyear1887
