The transmission mechanism of the electric impulses in a nerve cell is completely different from the mechanism of electronic conduction in metals. However, physics has an important role in explaining the dynamics of this process. In this work, we discuss some characteristics of these specialized cells. For this, we use the differential equation model of FitzHugh-Nagumo, especially in the analysis of the fixed points, stabilities and bifurcations. The main characteristics of the synaptic pulse propagation mechanism at a neuron, are shown in a simplest scenario to make possible the comprehension of the excitability phenomenon, in a geometrical context. Therefore, the analysis of the phase space is a fundamental item for the visual comprehension of the dynamic of nerve impulse propagation.
differential equations; nonlinearity; phase space
