To facilitate these interspecies comparisons, Supplemental Fig. The developmental processes in human embryos are, where appropriate, underscored with experimental and molecular data from other mammals, in particular mice, and if fitting, also with data from chickens. The descriptions of the components of the embryonic hearts follow the bloodstream, proceeding from the venous to the arterial pole. We describe the conspicuous morphological features of the developing human heart as they appear in consecutive stages of development. This is because their rotational options (“live” images) allow a much better understanding of the complex local topography than do “still” images and text.ĭistinct developmental features in staged human embryonic hearts The reader is encouraged simultaneously to read the text and inspect the corresponding interactive PDFs. The evidence can be inspected in the corresponding interactive 3D-pdfs (Supplemental Figs. We describe each of the stages, and the features distinguishing them from the previous stage. Our study has visualized such development in human embryos between 3.5 and 8 weeks of development, extending from Carnegie stages 9 through 23. To our knowledge, no comprehensive primer of cardiac development is presently available that is based on first-hand segmentation of structures of interest identified in histological sections. The spatial resolution and differential staining properties of these techniques, however, are still limited. In this respect, the description of human cardiac development based on magnetic resonance or fluorescent episcopic microscopy is instructive 12. Since nomenclature in the developing heart is notoriously variable, a combination of text and illustrations is necessary to provide an understandable account. Both qualitative 10 and quantitative 11 tabulations are available for the development of the human heart. This atlas, however, does not address the development of the heart in any detail. A recent example is the digital atlas of human development produced by the Amsterdam group 9. The advent of computer-aided reconstruction methods has significantly decreased the time necessary for the reconstruction of sectioned bodies. #Using picktorial 2019 serial#Such serial modifications, however, tend to propagate concepts rather than observations, and need to be assessed with caution. An example, documented in detail 7, is the frequently cited treatise of Kramer on the septation of the outflow tract 8. Because the methods used to make the models were labor-intensive, existing illustrations were often modified rather than new versions being created. All these successful approaches have in common that medical artists collaborated with embryologists who had artistic capacities themselves. Other examples are Blechschmidt’s models and drawings of human embryos 3, 4, and van Mierop’s images of the developing heart 5, which were redrawn by Netter 6. Examples of often used or cited classical models are Born’s “Plattenmodellen”, and Ziegler’s freehand models of embryos, which were studied and described by His 1, 2. Many aspects of embryonic development are topographically complex, such that three-dimensional (3D) models are exceedingly helpful in fully understanding temporal events. The remodeling of the interventricular foramen is complete at 7 weeks.Įmbryology is a visual discipline. Between 5.5 and 6.5 weeks, as the outflow tract becomes incorporated in the ventricles, the spiraling course of its subaortic and subpulmonary channels is transferred to the intrapericardial arterial trunks. Septation at the venous pole is completed at 6 weeks. The basic cardiac layout is established between 3.5 and 4.5 weeks. Pictorial timelines of structures highlight age-dependent events, while graphs visualize growth and spiraling of the wall of the heart tube. We describe the developmental appearance and subsequent remodeling of 70 different structures incrementally, using sequential segmental analysis. The models were visualized as calibrated interactive 3D-PDFs. We prepared detailed reconstructions of 12 hearts between 3.5 and 8 weeks post fertilization, using Amira® 3D-reconstruction and Cinema4D®-remodeling software. No comprehensive 3-dimensional primer of human cardiac development is currently available. Heart development is topographically complex and requires visualization to understand its progression.
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