3D atlas of human embryology: New insights in human development

Congenital malformations, which have an incidence of 3% in the human population, cause up to one-quarter of all neonatal deaths. Studying the intricate morphogenesis of the developing human body facilitates better understanding of the etiology of malformations. Embryonic development, however, is difficult to understand, despite modern technologies such as three-dimensional (3D) ultrasound. Based on histological sections we created a digital atlas with 14 interactive 3D models of human embryology and a database encompassing 34 embryos covering the first two months of human development. Approximately 15,000 histological sections from the Carnegie Collection were analyzed and up to 150 organs and structures per specimen were digitally labeled. This is the first and most extensive digital 3D Atlas of Human Embryology, containing all developing organ systems. Most organ systems presented in our 3D atlas perfectly resemble the descriptions and drawings of well-respected embryologists from decades ago. However, a number of detailed analyses of the development of the kidney, pharyngeal arch cartilages, and notochord show that the accepted descriptions of the development of these organs are based on comparative animal models rather than on factual observations in human specimens. The morphology presented in this atlas is directly connected to the original sections of the embryos in the Carnegie Collection - a connection that was in danger of being lost, with present-day textbook morphology becoming increasingly schematic and deviating from the original substrate. This atlas will therefore serve as educational and reference resource for students, clinicians, and scientists interested in human development and congenital diseases