Intracardiac flow patterns in early embryonic life. A reexamination.

Abstract

SUMMARY. MicroangiogTaphy, using methylene blue injected at eight vitelline vein sites, was performed on 156 developing chick embryos at Hamburger-Hamilton stages 14-22. Two stream patterns were observed. Type A coursed sequentially through the dorsal portion of the sinus venosus, the cranial segments of the primitive atrium and atrioventricular canal, the ventral parts of the primitive ventricle and conus cordis, and, finally, the left branchial arches. Type B coursed through the ventral portion of the sinus venosus, the caudal segments of the primitive atrium and atrioventricular canal, the dorsal parts of the primitive ventricle and conus cordis, and, finally, the right branchial arches. Both streams flowed in parallel fashion in the conus cordis. At Hamburger-Hamilton stages 17-18, the dye stream from the right lateral vitelline vein was chiefly type A, whereas that from the left lateral vitelline vein was type B. At Hamburger-Hamilton stages 19-22, those patterns reversed, i.e., the right lateral vitelline vein stream ran as type B, whereas the left lateral vitelline vein stream assumed type A pattern. The cranial-caudal relationship of the two streams at the primitive atrium and atrioventricular canal is not consistent with the hypothesis that these streams separately expand the future right atrium and left atnum. Their parallel direction at the conus cordis does not support the theory that spiral septation is initiated by two spiral streams. The longitudinal separation of the two streams at and beyond the branchial arches also argues against aortico-pulmonary septation as a consequence of flow streaming. Our observations do not support the traditional flow-molding theory. (Circ Res 53: 363-371, 1983) IT IS a traditional view that spiral streams of blood mold the primary heart tube during its development, and play a major role in the formation of the ventricular, bulbar, and aortico-pulmonary septa

Mechanisms in the Pathogenesis of Congenital Cardiac Malformations

“…Photographic analysis of the developing chick heart suggests that the position of the cardiac streams does not coincide with the sites between the forming endocardial and conotruncal cushions. [44] Aortic arch selection is related to the vector, volume, and direction of blood flow. Since arch vessel walls are a single cell thick and devoid of muscle tissue, vascular constriction is not possible.…”

Aortic Arch Morphogenesis and Flow Modeling in the Chick Embryo

“…Most investigations of aortic arch structure and function have been limited to ultrasound and contrast imaging [13], which at the moment, provide insufficient morphology and detailed 3D flow information to quantify the biomechanical events that occur during aortic arch remodeling. Several experimental flow visualization techniques including India ink, dye injection [6,11,12,15] and micro particle imaging [14,16,17] have been used to qualitatively and quantitatively document the hemodynamics in chick normal cardiac development. However, these studies focus primarily on 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Wang, Y. et al: Embryonic aortic arch morphogenesis and CFD 4…”

Altered hemodynamics in chick embryos after extraembryonic venous obstruction

“…The changing pattern of blood flow through the developing embryonic heart has been of interest to developmental biologists 1,2 . These studies, using the chick embryo, describe experiments in which blood from the yolk sac circulates through the heart and pharyngeal arch arteries.…”