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

First published online November 2, 2007
Journal of Experimental Biology 210, 3940-3945 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.009555

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB 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 Hedrick, M. S. Articles by Withers, P. C. Search for Related Content PubMed PubMed Citation Articles by Hedrick, M. S. Articles by Withers, P. C.

Lung ventilation contributes to vertical lymph movement in anurans

Michael S. Hedrick^1,*, Robert C. Drewes², Stanley S. Hillman³ and Philip C. Withers⁴

¹ Department of Biological Sciences, California State University, East Bay, Hayward, CA 94542, USA
² Department of Herpetology, California Academy of Sciences, San Francisco, CA 94103, USA
³ Department of Biology, Portland State University, Portland, OR 97207, USA
⁴ Zoology, School of Animal Biology M092, University of Western Australia, Crawley, Western Australia 6009, Australia

View larger version (27K): [in this window] [in a new window]   Fig. 1. Influence of pulmonary pressure on lymph sac pressures. Changes in dorsal, lateral and subvertebral lymph sac pressure as a function of pulmonary pressure in anesthetized C. marinus (left column) and L. catesbeiana (right column). All relationships were highly significant (P<0.001, N=11; linear regression) with r2 ranging from 0.19 to 0.72.

View larger version (4K): [in this window] [in a new window]   Fig. 2. Subvertebral and brachial sac pressures measured for one C. marinus during a single breath. Inspiration (solid horizontal line) and expiration (broken horizontal line) are indicated above the subvertebral pressure trace. Note that subvertebral sac pressure (top trace) increases during inspiration with little or no change in brachial sac pressure (bottom trace). During expiration there is a decrease in subvertebral sac pressure that is rapidly transmitted to the brachial sac.

View larger version (11K): [in this window] [in a new window]   Fig. 3. (A) Subvertebral sac pressure and brachial sac pressure during a breathing sequence in one C. marinus. Arrows indicate expiration events recorded in the subvertebral trace; note that rapid increases and decreases in brachial lymph sac pressure occur, but are predominantly during expiration. (B) Subvertebral sac pressure and pubic sac pressure during a breathing sequence in one C. marinus. Arrows indicate expiration events recorded in the subvertebral trace; note the rapid decreases in pubic sac pressure that occur during expiration.

View larger version (3K): [in this window] [in a new window]   Fig. 4. Frequency of occurrence (% of events) of combined brachial and pubic sac pressure events with inspiration and expiration in C. marinus. Brachial and pubic sac pressure events occurred much more frequently during expiration than during inspiration (*P<0.001; unpaired t-test). Values are means ± s.e.m. (N=10)

View larger version (4K): [in this window] [in a new window]   Fig. 5. Pressure changes (Pa) that develop in the brachial lymphatic sac during expiration in C. marinus and L. catesbeiana (means ± s.e.m.) compared with the estimated range of 0.5–1.0 cm (50–100 Pa; shaded box) of gravitational pressure necessary to raise lymph to the subvertebral lymph sac. Values were not different between the two species (P>0.05).

View larger version (53K): [in this window] [in a new window]   Fig. 6. Stylized models of C. marinus illustrating the hypothesis for the effects of lung ventilation on vertical lymph movement. (A) Lung deflation causes an increase in subvertebral lymph sac volume and a decrease in pressure, resulting in movement of lymph from the brachial lymph sac. Posterior skeletal muscles are also active during expiration, providing movement of lymph vertically in the posterior portion of the animal. Red arrows indicate the direction of lymph movement. (B) Lung inflation increases the pressure within the subvertebral, dorsal and lateral lymph sacs and forces lymph towards the anterior (Ant. LH) and posterior (Post. LH) lymph hearts. Red arrows indicate the direction of lymph movement.