The Sub-Pulmonary Conus And The Arterial Anastomosis As Important Sites Of Cardiovascular Regulation In The Crocodile Crocodylus porosus

Axelsson, Michael, Franklin, Craig E., Fritsche, Regina, Grigg, Gordon C. and Nilsson, Stefan (1997) The Sub-Pulmonary Conus And The Arterial Anastomosis As Important Sites Of Cardiovascular Regulation In The Crocodile Crocodylus porosus. Journal of Experimental Biology, 200 4: 807-814.

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Author Axelsson, Michael
Franklin, Craig E.
Fritsche, Regina
Grigg, Gordon C.
Nilsson, Stefan
Title The Sub-Pulmonary Conus And The Arterial Anastomosis As Important Sites Of Cardiovascular Regulation In The Crocodile Crocodylus porosus
Journal name Journal of Experimental Biology   Check publisher's open access policy
ISSN 0022-0949
Publication date 1997-02-01
Sub-type Article (original research)
Open Access Status File (Author Post-print)
Volume 200
Issue 4
Start page 807
End page 814
Total pages 8
Place of publication Cambridge, England
Publisher Company of Biologists
Language eng
Subject 270503 Animal Anatomy and Histology
Abstract We present evidence to support the hypothesis that the arterial anastomosis and the cogteeth-like valves located in the sub-pulmonary conus in the right ventricle are important sites of cardiovascular regulation in the crocodile Crocodylus porosus. The influence of the arterial anastomosis on the development of the 'foramen spike' in the left aortic pressure trace, which occurs at the onset of diastole when the pressures in the right and left aortas become equal, and on gastrointestinal blood flow was examined in unanaesthetised C. porosus using blood vessel occluders. Measurements of blood flow in the arterial anastomosis showed that, during non-shunting conditions, there was a substantial systolic blood flow from the right aorta into the coeliac artery. The total coeliac artery blood flow was the sum of the anastomosis flow from the right aorta plus the left aortic flow originating from the right aorta via the foramen of Panizza during diastole. During mechanically induced pulmonary-to-systemic shunting, the anastomosis blood flow was reversed, with blood flowing from the left to the right aorta. The magnitude of the 'foramen spike' was directly related to the vascular resistance in the anastomosis. When vascular resistance in the anastomosis was high, such as during mechanical occlusion, there was an increase in the right aortic to left aortic pressure gradient during systole which resulted in an increase the foramen spike amplitude. Recordings of right intraventricular pressure in unanaesthetised C. porosus showed spontaneous changes in right intracardiac systolic pressure. The pressure recordings were biphasic, with the second contraction (isometric) being highly variable in size, indicating the control of pulmonary outflow resistance, possibly via the 'cogteeth valves' located in the sub-pulmonary conus in the right ventricle.
Keyword cardiac physiology
circulatory control
Panizza
estuarine crocodile
Crocodylus porosus
Biology
Alligator Heart
Flow
Physiology
Dynamics
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Biological Sciences Publications
Ecology Centre Publications
 
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Created: Tue, 30 Nov 2004, 10:00:00 EST