This page will look better in a graphical browser that supports web standards, but is accessible to any browser or internet device.

Served by Samwise.


This model represents airway with one bronchus, one bronchiole, and an alveolus.

Model number: 0006

Run Model: 
    Help running a JSim model.
Java runtime required. Web browser must support Java Applets.
(JSim model applet may take 10-20 seconds to load.)


This model represents airway with one bronchus,one bronchiole, and one alveolus. The bronchus has largest resistance and smallest compliance. The bronchiole has smaller resistance and larger compliance than bronchus. The alveolus has the smallest resistance and largest compliance. Air flow is driven by a positive pressure ventilator.


where Pmouth is the pressure at the mouth; P scalar multiplies Pdrive, a function representing inhalation pressure; Pbronch, Pbonchiol and Palv are the pressure in the bronchus, bronchiole, and alveolus; Fmouth, Fbronch,Fbronchiol,and Falv are the air flow at the mouth, bronchus, bronchiole, and alveolus; Rbronch, Rbonchiol and Ralv are the resistances of the bronchus, bronchiole, and alveolus to the air flow; Combronch, Combonchiol and Comalv are the compliances of the bronchus, bronchiole, and alveolus; and Vbronchi, Vbonchiol and Valv are the volumes of air in the the bronchus, bronchiole, and alveolus.

The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.

Download JSim model project file


 M.G. Levitsky, Pulmonary Physiology, Sixth Edition, McGraw Hill, 2003.

 V.C. Rideout, Mathematical and Computer Modeling of Physiological Systems,
Prentice Hall, 1991, p137-143

Related Models

Key Terms

lung compliance, resistance, RC circuit, lung mechanics, airflow in bronchus, tidal volume, positive pressure ventilation, airway, PV curves, bronchus, bronchiole, alveolus

Model Feedback

We welcome comments and feedback for this model. Please use the button below to send comments:

Model History

Get Model history in CVS.

Posted by: Feng Gao


Please cite in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

[This page was last modified 14Mar18, 3:17 pm.]

Model development and archiving support at provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.