These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cardiac output and shunt during voluntary activity at different temperatures in the turtle, Trachemys scripta.
    Author: Krosniunas EH, Hicks JW.
    Journal: Physiol Biochem Zool; 2003; 76(5):679-94. PubMed ID: 14671716.
    Abstract:
    Red-eared slider turtles (Trachemys scripta) were chronically instrumented with blood flow probes for a long-term study of voluntary behavior in an enriched laboratory setting. Cardiovascular measures consisting of total cardiac output (Q(tot)), pulmonary blood flow (Q(pul)), systemic blood flow (Q(sys)), net cardiac shunt (Q(shunt)), heart rate (HR), and stroke volume (SV) were obtained during spontaneous activity at a constant body temperature (Tb=2 degrees C) and at unstable (variable) T(b)'s ranging from 19 degrees to 37 degrees C. The effects of temperature and activity differed between the pulmonary and systemic circuits, with increases in Q(sys) due to HR alone, while both HR and SV contributed to gains in Q(pul). At stable 20 degrees C, cardiovascular responses during diving, submerged swimming, and walking were qualitatively similar, and increases in Q(tot) during activity ( approximately 2 x resting levels) were due to greater gains in Q(pul) than Q(sys). At unstable T(b)'s and in general, net Q(shunt) while active depended on the integration of individual physiological influences such as heating, cooling, and initial behavioral state acting on the cardiovascular system. During activity, net left-to-right (L-R) shunts predominated at constant T(b) of 20 degrees C (mean shunt fraction approximately 30%-40%), while both net L-R and right-to-left (R-L) shunts of varying size were found at unstable T(b)'s (19 degrees - 37 degrees C).
    [Abstract] [Full Text] [Related] [New Search]