QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Simons, R. S. Search for Related Content PubMed PubMed Citation Articles by Simons, R. S. Social Bookmarking                         What's this?

Journal of Experimental Biology, Vol 202, Issue 5 563-577, Copyright © 1999 by Company of Biologists

JOURNAL ARTICLES

Running, breathing and visceral motion in the domestic rabbit (Oryctolagus cuniculus): testing visceral displacement hypotheses

RS Simons
Department of Biology, University of Utah, Salt Lake City, UT 84112, USA. rsimons@bio.umass.edu

The relative motion of the visceral mass may be important to ventilation during running. A visceral piston hypothesis predicts that, during galloping, cranial motion of the liver during expiration and caudal motion of the liver during inspiration may characterize efficient quadrupedal mammalian locomotion. Although a theoretical model based on vibration mechanics casts doubt on this prediction, only limited direct measurements of visceral mass motion during galloping have been reported. In the present study, mechanical interactions between running, breathing and liver oscillations in the domestic rabbit are recorded using synchronized videographic, cineradiographic and pneumotachographic techniques. The analysis focuses on the variation in locomotor-respiratory coupling (LRC) and on the relative position of the liver. Results from running rabbits show (1) variation in phase angle between the locomotor and respiratory periods that is inconsistent with the 1:1 LRC ratio that has been reported for other galloping mammals; (2) a tendency towards a 1:1 LRC ratio at higher speeds and stride frequencies; and (3) that the relative motion of the liver is caudal during expiration and cranial during inspiration, which is inconsistent with the visceral piston hypothesis. The data presented here are generally consistent with the theoretical vibration mechanics model for liver motion and with a pneumatic stabilization hypothesis that the lungs serve an important role in the stabilization of the thorax during locomotion.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				J. E.A. Bertram and A. Gutmann Motions of the running horse and cheetah revisited: fundamental mechanics of the transverse and rotary gallop J R Soc Interface, June 6, 2009; 6(35): 549 - 559. [Abstract] [Full Text] [PDF]

				N. Schilling and R. Hackert Sagittal spine movements of small therian mammals during asymmetrical gaits J. Exp. Biol., October 1, 2006; 209(19): 3925 - 3939. [Abstract] [Full Text] [PDF]

				T. Landberg, J. D. Mailhot, and E. L. Brainerd Lung ventilation during treadmill locomotion in a terrestrial turtle, Terrapene carolina J. Exp. Biol., October 1, 2003; 206(19): 3391 - 3404. [Abstract] [Full Text] [PDF]

				M A Pellegrino, M Canepari, R Rossi, G D'Antona, C Reggiani, and R Bottinelli Orthologous myosin isoforms and scaling of shortening velocity with body size in mouse, rat, rabbit and human muscles J. Physiol., February 1, 2003; 546(3): 677 - 689. [Abstract] [Full Text] [PDF]