21- Summary of Vascular Structuring by the Amniotic Cavity

The study of vascular structuring by the amniotic cavity highlights the essential integration between the vascular system and the vitelline system. During embryonic development, the amniotic cavity, initially similar in size to the vitelline vesicle, plays a fundamental role by allowing the resorption of the vitelline system towards the center of the embryo. This process, referred to as zone B, is crucial for the organization of the aortic system and manifests through transverse and thoracic movements. The growth of the amniotic cavity leads to a reorganization of internal spaces, promoting the integration of embryonic structures.

The notochordal system acts as the main driver of this dynamic, influencing the development of the neural tube and the organization of the primitive vascular system. The processes of cephalization, cardialization, diaphragmatization, and hepatization are also integrated into this movement, allowing a complex reorganization of internal systems. The vitelline vesicle, as a source of primitive information, interacts with the outside to facilitate the formation of the digestive tract and the integration of the venous system. Thus, the amniotic cavity, as it grows, plays a central role in the fusion of embryonic structures, leading to a harmonious integration of the external coelom into an internal coelom, essential for embryonic development.