medullary plate n.
See neural plate.
The anterior wall of this passage connects together the medullary plate and the notochordal ridge of the hypoblast.
The medullary plate is thickened at the two sides, and is grooved in the median line by a delicate furrow (fig. 72, r).
The central part constitutes a somewhat prominent ridge, the axial part of it being the medullary plate.
In other types the epiblast is several cells deep even before the differentiation of a medullary plate.
The medullary plate is just established, and is marked by a shallow groove which becomes deeper in front.
The medullary plate is more distinct, and a shallow but unmistakable medullary groove has made its appearance.
This plate is the medullary plate; along its axial line is a shallow groove—the medullary groove (mg).
The medullary plate of the nervous system is laid down about the fourteenth day, and the nasal area is observable.
It becomes obliterated shortly after the appearance of the medullary plate.
The hypoblast cells are flattened laterally, but become columnar beneath the medullary plate (fig. 142).