Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down

Biology Letters
By: , and 

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Abstract

Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down
Series title Biology Letters
DOI 10.1098/rsbl.2015.0592
Volume 11
Issue 10
Year Published 2015
Language English
Publisher Royal Society
Contributing office(s) National Wildlife Health Center
Description e0592
Online Only (Y/N) N
Additional Online Files (Y/N) N