Heart anatomy and developmental biology.

The subject of heart development has attracted the interest of many embryologists over the last two centuries. As a result, the main morphologic features of the developmental anatomy of the heart are already well established. Although there are still some controversial points, and there is probably much descriptive work yet to be done, emphasis is currently being placed on developmental mechanisms rather than simply on descriptive facts. The availability of new techniques and the overall advances in biological research are placing heart embryology in a new perspective. Today, we do not simply ask whether one or another embryonic structure arises further right or further left; instead, we are studying how cells, tissues, and their microenvironment interrelate at the several levels of biological organization (from the gene upwards) so as to give rise to a mature organ with a distinct shape and well-established functions. This paper attempts to review some of the basic aspects of the developmental anatomy of the heart. Descriptive embryology is used here as a tool. Emphasis is placed on developmental mechanisms, and on the present knowledge of how these mechanisms are related to the structural development of the heart.