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An Introduction To Non-aristotelian Systems And General Semantics.

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C Fig. 1
Diagrams representing the relations of neurons in five types of reflex arcs: A, simple reflex arc; B, chain reflex; C, a complex system illustrating allied and antagonistic reflexes and physiological resolution; D, a complete system illustrating allied and antagonistic reflexes with a final common path; E, a complex system illustrating the mechanism of physiological association A,A, association neurons; C,C',C,C1, and C1, centres (adjustors) ; E,E',E", El, and El, effectors; FCP, final common path; R,R',R",R1, and R2, receptors.
'The structure of the simple reflex circuit is diagrammatically illustrated in Fig. 1, A. The receptor (R) may be a simple terminal expansion of the sensory nerve-fiber or a very complex sense organ. The effector (E) may be a muscle or a gland. The cell body of the afferent neuron (1) may lie within the center (C) or outside, as in the diagram. ... A simple reflex act involving the use of so elementary a mechanism as has just been described is probably never performed by an adult vertebrate. The nervous impulse somewhere in its course always comes into relation with other reflex paths, and in this way complications in the response are introduced. .. .
'Separate reflex circuits may be so compounded as to give the so-called chain reflex (Fig. 1, B). Here the response of the first reflex serves as the stimulus for the second, and so on in series. The units of