In the

development Development or developing may refer to: Arts *Development hell, when a project is stuck in development *Filmmaking, development phase, including finance and budgeting *Development (music), the process thematic material is reshaped * Photograph ...

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 The amniotic sac, also called the bag of waters or the membranes, is the sac in which the embryo and later fetus develops in amniotes. It is a thin but tough transparent pair of membranes that hold a developing embryo (and later fetus) until shor ...

and the

yolk sac The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far ...

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.Drew, Ulrich, ''Color Atlas of Embryology'', p. 64, Thieme Press 1995, . When the development of the

notochord In anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord consis ...

is complete, the neurenteric canal normally closes.

References

Embryology {{Portal bar, Anatomy