Neurenteric canal

In the development of vertebrate animals, during the 6th Carnegie Stage, the proximal part of the notochordal canal persists temporarily as the neurenteric canal (also known as the "axial canal"), which forms a transitory communication between the amniotic sac and the yolk sac cavities. The neurenteric canal is thought to play a role in the maintenance and adjustment of pressure between the amniotic sac and the yolk sac. When the development of the notochord is complete, the neurenteric canal normally closes.