Fluidic oscillators display a unique feature: from a constant input flow, they generate an output that alternates both temporally and spatially, all without the necessity for any moving components. However, there have been varying theories proposed to explain the underlying mechanisms. In this study, we provide experimental arguments that the functioning of a single-feedback loop fluidic oscillator can be effectively modeled and interpreted using the Fitzhugh-Nagumo equations. We explore the connection between the Fitzhugh-Nagumo system and the momentum equations, as well as a fluid capacitance. Our findings reveal a complex interplay of secondary flows within the oscillator, which appears to facilitate the self-sustained oscillation.