10-Formation of the Upper Intestine

The formation of the upper intestine is a complex embryological process, characterized by the movement of the endoderm, which transforms from a sac into a tube through mechanisms of flexion and elongation. This process is orchestrated by the amniotic cavity, which encompasses the embryo and integrates the digestive tube. Vascular dynamics, particularly the closure of the neural tube and the approximation of the endocardial tubes, play a crucial role in the formation of the pharyngeal intestine, thus delimiting the longitudinal axis of the embryo.

At approximately fifteen days of development, the embryo divides into three distinct parts, with a head disproportionate to the trunk. The flexion of the embryo is influenced by the vascular system, leading to the formation of folds that structure the endodermal, ectodermal, and mesodermal tissues. The branchial arches, such as the mandibular arch and the hyoid arch, contain specific information and are oriented towards the base of the skull, playing an essential role in the development of facial structures. The rupture of the buccopharyngeal membrane marks the beginning of mouth formation, integrating vascular elements and influencing the development of the palate and teeth.

In summary, the formation of the upper intestine and facial structures results from dynamic interactions between different embryonic tissues, highlighting the importance of biodynamic processes in embryological development.