The propagation of signals in nerves is characterized by complexity where the interactions between the electrical signal and accompanying mechanical and thermal effects must be taken into account. That is why in the modelling of wave phenomena the knowledge from physiology, physics, and mathematics must be cast into a whole. In this paper the wave phenomena in nerves are characterized from the viewpoint of complexity and interdisciplinarity, followed by the analysis of principles and criteria in the modelling of biological systems. The central part is the description of the step-by-step approach in building up a coupled mathematical model of signal propagation in axons. Attention is paid to the coupling forces which link the single waves into an ensemble. The mathematical description of the model is presented in the Appendix.
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