Energy metabolism in the whole animal revisited

Dimensional analysis of animal with regard to those structures and functions which affects the rate of energy metabolism can be conducted on the basis of either geometric or eleastic similarity. Predictions of the trelationships between various structures and functions and body mass are dependent of the type of similarity assumed. Comparison of the relationships between numerous physiological variables and body mass resported in the literature and those predicted from geometric and elastic similarity indicates that the preponderance of predications from elastic similarity are in better agreement with the observed values than are the prediction from geometric similarity. It appears that the components of the cardiovascular system are scaled in accordance with elastic similarity. For this reason, cardiac output is proportional to body mass raised to the 34 power. The biochemical basis for the relationship between cardiac output and the rate of energy metabolism is discussed.