We describe a novel student course in membrane physiology in which students record their own nasal potential difference, i.e., the transepithelial potential difference of the respiratory mucosa in the nose. The nasal potential difference monitors directly, and in vivo, changes in the apical cell membrane potential of the respiratory mucosa induced by activators and inhibitors of ion channel activities. Basic principles of transepithelial fluid transport are taught by applying an appropriate perfusion protocol to the respiratory epithelium to either depolarize or hyperpolarize the membrane potential of the luminal cell side, thereby increasing or decreasing the nasal potential difference. This course was given at the Department of Physiology at the University of Wurzburg in 1997, and responses of the students as reported on questionnaires were mainly positive.