Abstract
1. 1. Voluntary undisturbed dives by Crocodylus porosus were short in duration (3.08 ± 1.87 min, mean ± SD) and accompanied by a small but significant bradycardia (14.3 ± 5.9% drop). 2. 2. When crocodiles were disturbed underwater there was a rapid onset of “fright” bradycardia, to 65 ± 6.0% of surface heart rates and dive durations were prolonged to 19.6 ± 1.8 min. 3. 3. The development of “fright” bradycardia was not accompanied by any increase in intratracheal pressure or expulsion of lung gas. However, sustained contraction of the abdomen and expansion of the thorax revealed a redistribution of air anteriorly within the lungs. 4. 4. We propose that the redistribution of air within the lungs may generate an afferent signal which potentiates the initiation of a severe, dive-prolonging bradycardia.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Comparative Biochemistry and Physiology Part A: Physiology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
