Dynamic viscoelastic properties of the canine trachea

The dynamic elastance (E) and viscous resistance (R) of the canine intrathoracic trachea were determined by submitting excised tracheal segments to periodic variations of pressure at frequencies between 0.5 and 9 Hz, and by relating simultaneous transmural pressure and volume variations. Mean values of E and R are, respectively, 17.3 cmH2O.cm-1 and 0.16 cmH2O.cm-1.s, or, expressed in volume changes per cm length of the trachea, 53.5 cmH2O.ml-1 and 0.49 cmH2O.ml-1.s. E and R increase at higher longitudinal tension of the trachea and under the influence of acetylcholine.