Cardiovascular physiology in dolphins and other cetaceans
Publication Date
1-1-2023
Document Type
Article
Publication Title
The Physiology of Dolphins
DOI
10.1016/B978-0-323-90516-9.00011-7
First Page
77
Last Page
105
Abstract
The cardiovascular system in cetaceans follows the general mammalian model but is custom designed for individual species. Notable features include (a) a compliant, elastic ascending aorta and aortic arch, (b) the retia mirabilia, (c) venous plexuses in the head and tracheo-bronchial tree, (d) prominent epidural veins, (e) diaphragmatic caval slings, and (f) thermoregulatory plexuses. During high-speed surface and subsurface swimming of more active porpoises and dolphins, high heart rates, enlarged hearts, and higher affinities of hemoglobin for oxygen (O2) are postulated to maximize lung-to-muscle O2 transport just as during exercise of terrestrial mammals. However, during dives, the cardiovascular dive response (bradycardia and vasoconstriction) is variable and serves to regulate the depletion of O2 stores according to the nature of a given dive. Depth, dive duration, exercise, lung volume reflexes, and cognitive control have all been postulated to influence heart rate during the dive.
Keywords
Cardiac output, Diaphragmatic sphincter, Dive response, Epidural vein, Heart size, Rete mirabile, Stroke volume, Venous plexus, Windkessel
Department
Moss Landing Marine Laboratories
Recommended Citation
Paul J. Ponganis and Birgitte I. McDonald. "Cardiovascular physiology in dolphins and other cetaceans" The Physiology of Dolphins (2023): 77-105. https://doi.org/10.1016/B978-0-323-90516-9.00011-7
