The structures of segmentation and possible genetic determinants are discussed. This chapter portrays the movements associated with neural tube closure, and shows how birth defects such as Anencephaly and Spina Bifida can occur. The essential nature of neural crest cells, which appear during neurulation, is shown and explained. The heart is the first organ of the body to function. This segment simulates the development of the heart from the initial stages of precardiac mesodermal cells to the formation and elaboration of its complicated chambers and vessels.
Attention is given to how human heart development differs from that of lower vertebrates.
As one of the major organs, eye development is followed in movies and text through the embryonic and fetal periods. Ear The ear, like the eye, is a special sense organ, and the two share certain developmental processes. This segment shows the development of the ear from the initial invagination of the otic placode to the final formation of the ear and its associated structures. The complicated origin and differentiation of the branchial arches is shown through color-coded movies with explanatory text concerning the fate of these structures. The development of the gastrointestinal tract is portrayed, with arrows and text, as it undergoes its well known, but poorly visualized, gut rotation.