Neyrula

Neurula (from the Greek neuron - nerve) is the stage of embryonic development of chordates at which the neural tube is formed.

At the neurula stage, the neural plate emerges from the ectoderm. The edges of the neural plate rise and close to form the neural groove. Then the edges of the neural groove grow together, and the neural tube is formed - the rudiment of the central nervous system.

In vertebrate embryos, the neurula is formed at the end of the 3rd week of development. The neural tube becomes the basis for the formation of the brain and spinal cord.

At the neurula stage, somites are also formed - the rudiments of body segments and muscles. The somites are located in pairs on both sides of the neural tube.

Thus, the neurula is the most important stage of vertebrate embryogenesis, when the foundations of their nervous system and body segmentation are laid.