E. Christian et Gc. Grigg, Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: a combined microscopic and electrophysiological study, COMP BIOC A, 123(1), 1999, pp. 17-23
Citations number
17
Categorie Soggetti
Animal Sciences",Physiology
Journal title
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY
We mapped the sequence of ventricular depolarization in the crocodile Croco
dylus johnstoni. We also attempted to find specialized conduction tissue wi
thin the ventricular myocardium. Electrical recordings with miniature multi
-point electrodes revealed two strands of rapidly conducting tissue (channe
ls) within the interventricular septum, suggestive of conductive tissue pat
hways. From these septal channels, wavefronts of excitation swept around ea
ch ventricle. Electrical recordings did not indicate that there was conduct
ive tissue in the wall of either ventricle. Similarly, microscopic studies
of the septal channels provided no indication of specialized conductive tis
sue. We suggest that the channels of early septal depolarization provide th
e crocodile heart with a high speed depolarization pathway functionally ana
logous to a rudimentary conductive system. (C) 1999 Elsevier Science Inc. A
ll rights reserved.