Net cardiac shunts in anuran amphibians: physiology or physics?

• DOI: 10.1242/jeb.105536
• Publication Date: 2014-06-06T02:14:35Z
• Authors: Stanley S. Hillman; Michael S. Hedrick; Zachary F. Kohl
• Keywords: Oxygen; 0301 basic medicine; Pulmonary Circulation; 03 medical and health sciences; Heart Rate; Hemodynamics; Animals; Bufo marinus; Heart; Cardiac Output

Amphibians have a single ventricle and common conus arteriosus that produces an equal pressure to the parallel pulmocutaneous systemic vascular circuits. The distribution of blood flows between () circuits (net cardiac shunt) varies with number environmental conditions behaviours; although autonomic regulation pulmonary resistance conductance has been emphasized, little attention paid possible contribution passive physical characteristics two changes associated variation in output. In this study, we re-analysed three recent studies recorded net shunts cane toad (Rhinella marina) under variety treatments. all studies, were linearly related output (), but slope was threefold higher for compared as predicted by relative increases from perfused preparations where humoral control eliminated. Our analysis indicates shunt is primarily physical, rather than physiological,