Related Experiment Video
Updated: Aug 5, 2026

Combining Volumetric Capnography And Barometric Plethysmography To Measure The Lung Structure-function Relationship
Published on: January 8, 2019
A closed lung system study of inert gas absorption
Abstract:
The demonstration that the rate of rise of the alveolar fraction of nitrous oxide is enhanced when the inspired N2O concentration is high is termed the "concentration effect." A similar effect on a second gas has been termed the "second gas effect". These effects have been observed in open systems and attributed to differential changes between inspired and expired ventilation. The purpose of this investigation is to study these effects in a closed system. A breath-holding maneuver was utilized with a high and a low N2O concentration in argon and oxygen. The results indicate that breath holding with a high N2O concentration "concentrates" both the alveolar fraction of N2O and argon. These results are attributable to alveolar volume shrinkage as a consequence of the large absorption of N2O by the pulmonary blood. A mathematical model verifies this interpretation and suggests that volume shrinkage can be important in breath-holding maneuvers designed for noninvasive measurement of cardiac output and lung tissue volume.
More Related Videos
Related Concept Videos
Gas Exchange and Transport
Physical Principles Governing Gas Exchange
Gas Laws Governing Respiration
The behavior of gases is guided by Dalton's Law of partial pressures and Henry's Law.
Dalton's Law asserts that the total pressure exerted by...
External and Internal Respiration
Adsorption of Gases on Solids
Adsorption Isotherms II
Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...

