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Link to March 2003 article in J. Appl. PhysiologyPredecessor text on venous return
Topics in Thermoregulation

I hope you will find what I've posted useful. Your comments by email to
would be welcome. I would gladly follow up on topics of common interest.

George Brengelmann
Professor Emeritus
Department of Physiology and Biophysics
University of Washington

A critical analysis of the view that right atrial pressure determines venous return

Those wishing a reprint of my article published in the March, 2003, issue of the Journal of Applied Physiology can download it from: this link I would be happy to discuss issues raised in the paper via email.

More on what's wrong with stating that venous return is determined by right atrial pressure?

Prior to the appearance of the present paper, preliminary work on this topic was posted on this site. This material was the predecessor of a manuscript excoriated by reviewers of the American Journal of Physiology, Heart and Circulation. In case readers of the J. Appl. Physiol. paper may be interested in a somewhat different presentation, I will continue to make this text accessible . Comments are invited. Also see an early description of an imaginary experiment, i.e., a "thought" or "gedanken" experiment which I believe illustrates how one might alter right atrial pressure and record cardiac output and venous return in an experimental preparation similar to the one used by Guyton and his co-workers. It highlights the importance of the restraint that the total blood volume within the peripheral vasculature remain constant for the range of data spanned by a venous return curve.

Topics in thermoregulation

For a related site of interest to students of body temperature regulation and responses of humans to various stresses, see the site maintained by Dr. Daniel Sessler (, with links to the extensive work of his Outcomes Research Group.

Body temperature regulation and the body temperature set point in the neutral zone.
This includes a series of pages on:
1. Basic issues of thermoregulation, e.g.: What is the neutral zone? What is the set point? -- treated by introduction to properties of simple control systems: thermostatic, proportional, and dual proportional control -- concluding with the assertion that common interpretations of core temperature changes in terms of set point changes are fallacious.
2. The rationale, some of the methods, and some discussion of the results of our study of body temperature regulation in humans under neutral zone conditions.

A practical tip, so to speak.
Many have asked for details of the method for holding rectal probes in place for long-term monitoring of rectal temperature. For a brief description, click here.

Temperature regulation in congestive heart failure
For an abstract of my review article in Cardiologia, click here
This article has been difficult to acquire for some correspondents whose libraries do not carry this journal published in Italy. I have prepared an HTML version for it but do not feel free to post it because of uncertainty about copyright. Though I recall signing no copyright agreement with Cardiologia, I am assuming that I should not make this document available for general access. However, I also believe that I am free to send copies to those who request reprints. I'll respond to requests by email

In development

Again --Your comments by email to
would be welcome.