Location of pacemaker in chick embryo heart at the time of initiation of heartbeat

LH Van Mierop - American Journal of Physiology-Legacy …, 1967 - journals.physiology.org
LH Van Mierop
American Journal of Physiology-Legacy Content, 1967journals.physiology.org
VAN MIEROP, LODEWYK HS Location of pacemaker in chick embryo heart at the time of
initiation of heartbeat. Am. J. Physiol. 2 I 2 (2): 407-q I 5. 1 g67.-Electrograms and
intracellular action potentials were recorded of the hearts of chick embryos during the 1st
week of incubation. All studies were carried out with the embryos in situ and with
spontaneously beating hearts. It has been possible to show that the pacemaker even before
initiation of the heartbeat (8 somite embryos) is already located in the sinoatrial portion of the …
VAN MIEROP, LODEWYK HS Location of pacemaker in chick embryo heart at the time of initiation of heartbeat. Am. J. Physiol. 2 I 2 (2): 407-q I 5. 1 g67.-Electrograms and intracellular action potentials were recorded of the hearts of chick embryos during the 1st week of incubation. All studies were carried out with the embryos in situ and with spontaneously beating hearts. It has been possible to show that the pacemaker even before initiation of the heartbeat (8 somite embryos) is already located in the sinoatrial portion of the heart, ie, there is no pacemaker shift from ventricle to sinus venosus during the early phases of cardiac development, as is often stated. The (sino) atria1 conduction time has been found remarkably constant at go-100 msec throughout development. Short bursts of sinoatrial ectopic beats often occurred on impaling a sinoatrial cell. Such tachycardia never resulted from impalement of a ventricular cell. Ventricular action potentials rarely exhibited prepotentials, and then only in the younger specimens. action potentials of chick embryonic heart; initiation of heartbeat in a chick embryo; initiation of electrical phenomena in chick embryo heart
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