Saltatory conduction: uncovering the mind of biology students

Abstract

Saltatory conduction of action potentials is part of the Biology curriculum which is taught since Secondary Education and it is considered an extremely important concept when teaching neuron physiology and the nervous system. However, students' understanding of this particular concept implies several difficulties, such as the conceptualization of “local” currents which allow the self-regeneration of an action potential. The purpose of this work is, therefore, to answer the following question: what do Biology students understand by “saltatory conduction”? This aims to identify students' difficulties in order to help us improve our teaching practices. So as to answer this question, a survey with open and closed questions was conducted among first year Biology students from Instituto de Profesores “Artigas”. The results show that, even though students can establish an association among saltatory conduction, myelin sheath and nodes of Ranvier, they understand saltatory conduction in a vague and superficial way. Only few highlighted the importance of an inversion in the membrane potential in the active zone, and even fewer students made reference to the density of the sodium channels in the nodes of Ranvier, or to the local currents. These results cast doubts on whether some students consider the use of the term “saltatory” as literal.