Guyton's venous return curves should be taught at medical schools (complete English translation of Japanese version).

Guyton's most significant contributions are the exploration into the development of venous return and circulatory equilibrium. Recently, several physiologists challenged the validity of venous return as a function of venous pressure. Guyton's experiment in effect controlled venous pressure by changing cardiac output. Thus, critics claimed that cardiac output is the determinant of venous return. This claim is true, but in the presence of constant stressed volume, venous return and venous pressure have a fixed reciprocal relationship. Thus, it is meaningless to argue which one is the independent variable. We fully support Guyton's venous return and in particular circulatory equilibrium. Guyton's framework should be taught at medical schools worldwide.