Model number


Concentration profiles in capillary and tissue when exchange is diffusion limited. Includes axial and radial diffusion in a 2-D (x,r,t) partial differential equation problem.


  This is a modified version of a BTEX20 model where the cell
  has been divided into 20 sub-compartments. The exchange
  coefficients between the sub-compartments are calculated to
  solve the radial diffusion equation. This is a two-dimensional
  partial differential equation.

  Solutions are displayed in 3 formats:
    Wire Mesh (RUN LOOPS), and
    Vertically Exaggerated Wire Mesh (RUN LOOPS).

  NOTA BENE: To construct the wire mesh plots requires 21*21=441
  solutions. The program takes significant time to run.

  The vertically exaggerated wire mesh shows that the low
  tissue diffusion coefficient results in a "trailing wave"
  of concentration in the tissue. This model was generated
  by MPC (the Modular Program Constructor). 


The wire mesh concentration profiles in capillary and tissue when exchange is diffusion limited.

fig 1



     Advection-diffusion partial differential equation in cylindrical coordinates without angular dependence


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

Help running a JSim model.

  Bassingthwaighte JB, Knopp TJ, and Hazelrig JB. 
  A concurrent flow model for capillary-tissue exchanges. 
  In: Capillary Permeability (Alfred Benzon Symp. II), edited 
  by Crone C and Lassen NA. Copenhagen: Munksgaard, 1970, pp 60-80.
Key terms
diffusion limited
radial diffusion
wire mesh
partial differential equation
Modular Program Constructor

Please cite https://www.imagwiki.nibib.nih.gov/physiome 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.

Model development and archiving support at https://www.imagwiki.nibib.nih.gov/physiome 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.