Plate 27
|
PLATE NUMBER |
STAGE |
TIME |
ORIENTATION |
IMAGE |
|
27 |
Neural groove stage Embryo stage 18 |
19 h 45 min p.f. |
Dorsal
Ventral |
Central transversal section |
Neural groove stage (embryo stage 18)
At this stage, the neural tube closes. This is caused by the movement of the bottle cells of the neural groove toward the inside, movement of the lateral epithelial layer over the surface of the neural tube and the lifting of the lateral neurectoderm by the somitogenic mesoderm. Cells within the neural tube orient themselves towards the center of the tube. Notochord maintains its contact with the floor of the neural tube. mesoderm of the lateral plate is double-layered.