Human embryo—length, 2 mm. Dorsal view, with the amnion laid open. X 30.
|- style="text-align: center;" class="hiddenStructure"
| colspan="2" |
|- style="text-align: center; line-height: 1;" class="hiddenStructure"
| colspan="2" |
|- class="hiddenStructure"
|Latin
|colspan="2"|
|- class="hiddenStructure"
|
|colspan="2"|[subject #7 ]
|- class="hiddenStructure"
|System
|colspan="2"|
|- class="hiddenStructure"
|Carnegie stage
|colspan="2"|[9]
|- class="hiddenStructure"
|Days
|colspan="2"|
|- class="hiddenStructure"
|Precursor
|colspan="2"|
|- class="hiddenStructure"
|Gives rise to
|colspan="2"|Neural tube
|- class="hiddenStructure"
|MeSH
|colspan="2"|[]
|- class="hiddenStructure"
|Dorlands/Elsevier
|colspan="2"|[g_12/12402700]
|}
Between the neural folds is a shallow median groove, the neural groove. The groove gradually deepens as the neural folds become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into a closed tube, the neural tube or canal, the ectodermal wall of which forms the rudiment of the nervous system.
