Epicardial formation in embryonic chick heart: computer-aided reconstruction, scanning, and transmission electron microscopic studies.

摘要: Epicardial formation in the embryonic chick heart from initial to final stages was revealed by means of computer-aided reconstructions based on serial resin sections for light microscopy, with further detailed observations using scanning and transmission electron microscopy. The origin epicardium recognized as protrusions mesothelial cell clusters right side external surface sinus venosus at 23 somites (stage 14+). These elongated give rise several villous processes, tips which eventually touched dorsal wall 30 17). Originating these adhesion sites, cells spread gradually onto myocardial all directions form a monolayered sheetlike cover. Thus, stage 23, ventricle completely overlaid epicardium, blood-island-like structures appeared within subepicardial layer. atrium not enveloped until 25, extreme distal end bulbus cordis reached advancing 27. A chronological table epicardial is presented.