Intraspecific scaling of arterial blood pressure in the Burmese python

Abstract

Abstract Interspecific allometric analyses indicate that mean arterial blood pressure (MAP) increases with body mass of snakes and mammals. In snakes, MAP increases in proportion to the increased distance between the heart and the head, when the heart-head vertical distance is expressed a ρgh, and the rise in MAP is associated with larger heart to normalize wall stress in the ventricular wall. Based on measurements of MAP in Burmese python ranging from 0.9-3.7 m in length (0.20-27 kg), we demonstrate that although MAP increases with body mass, the rise in MAP is merely half of that predicted by heart-head distance. Scaling relationships within individual species, therefore, may not be accurately predicted by existing interspecific analyses.