II Studies on the Physiology of the Trachea

Abstract

The tracheal wall was penetrated by a micro-electrode and the electrical potential gradient was measured from the inner surface and continuously at different depths of the tracheal wall compared with the external surface. Three different layers were electrophysiologically identified; the mucous blanket of the trachea had a varying negative potential with respect to the outside surface, due to fluctuations in ion concentration of the mucous itself; the borderline to the ciliary cell layer was easily recognized. Thus the method can be used for intravital measuring of the thickness of the mucous layer; the penetration of the ciliated and goblet cells gave negative potentials with amplitudes of about 30- 52 mV; below the submucous structures negative potentials were obtained with amplitudes of 30-70 m V corresponding to the smooth muscle cell layer between the cartilaginous rings.