Anatomical evidence for a countercurrent heat exchanger associated with dolphin testes
Article first published online: 26 JAN 2005
Copyright © 1992 Wiley-Liss, Inc.
The Anatomical Record
Volume 232, Issue 1, pages 150–156, January 1992
How to Cite
Rommel, S. A., Pabst, D. A., McLellan, W. A., Mead, J. G. and Potter, C. W. (1992), Anatomical evidence for a countercurrent heat exchanger associated with dolphin testes. Anat. Rec., 232: 150–156. doi: 10.1002/ar.1092320117
- Issue published online: 26 JAN 2005
- Article first published online: 26 JAN 2005
- Manuscript Accepted: 22 MAY 1991
- Manuscript Received: 1 FEB 1991
Cetaceans possess cryptic testes that lie within the abdominal cavity, that are surrounded by primary locomotor muscles, and that are presumably exposed to core or above core body temperatures. It has remained a question as to how cetaceans produce and store viable sperm at these high temperatures. We offer anatomical evidence for a two layer arterio-venous countercurrent heat exchanger at the cetacean testis. Subcutaneous veins from the peripheral surfaces of the dorsal fin and flukes carry cool blood from the fins to the lumbo-caudal venous plexus. The lumbo-caudal venous plexus is juxtaposed to the spermatic arterial plexus, which supplies the testis. Venous plexus flow is from the ventro-lateral margins of the visceral cavity towards the vena cava. Arterial plexus flow is from the aorta towards the ventro-lateral margins of the visceral cavity and into the testis. The existence of a countercurrent heat exchanger suggests that cetaceans potentially compensate for detrimental effects of core temperatures on sperm viability and storage by regulating the temperature of blood flow to the testis.