Éléments de physiologie humaine (1907) Éléments de physiologie humaine elementsofhumanp05star Année : 1907-fibres nerveuses (tissus conducteurs) 183 et courant dans le même sens. Ce courant est appelé le electrotonic courant. Il ne doit pas être confondu avec le courant de l'action, qui prend naissance à l'un des pôles, qu'à faire ou casser de l'actuel, et il est transmis de là, sous la forme d'une vague avec une vitesse d'environ 30 mètres par seconde. L'electrotonic courant est développé instantanément, et dure tout le temps que le courant circule dans le nerf. Sa production
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Elements of human physiology (1907) Elements of human physiology elementsofhumanp05star Year: 1907 NERVE-FIBRES (CONDUCTING TISSUES) 183 current and in the same direction. This current is called the electrotonic current. It must not be confounded with the current of action, which originates at one of the poles, only at make or break of the current, and is transmitted thence in the form of a wave with a measurable velocity of about 30 metres per second. The electrotonic current is developed instantaneously, and lasts the whole time that the current is flowing through the nerve. Its production is dependent on the occurrence of polarisation between the sheathing and conducting part of the nerve-fibre and may be exactly reproduced on a model consisting of a core of zinc or platinum wire in a casing of cotton soaked with ordinary salt solution. Although thus physical in origin, its production is dependent on the vitality of the nerve, and so is not to be confounded with the simple spread of current. Glass tube containing 0-6%%%%%%%%%%%%%%%% Na Cl. Pt.wire Apparatus for iruitating the polarisation phenomena in medullated nerve (' Kcrnlciter ' model). The polarisation phenomena resulting from the passage of a constant current through a medullated nerve can be studied on a model made up of a glass tube filled with normal salt solution, containing a platinum or zinc wire stretched through it (Fig. 89). On leading a current through a and b, and connecting c and d with a galvanometer, a current will be observed in the extrapolar portion of the model in the same direction as in the intrapolar. That this spread of current is due to polarisation is shown by the fact that, if the model be made of zinc wire immersed in saturated zinc sulphate solution, where no polarisation can occur, the spread of current to the extrapolar area is also wanting. If we ex- mine the phenomena taking place at the anode, we see that a current passes here through an electrolyte to the conducting core.
