blastopore's Usage Examples:

The embryo now consists of two layers of cells, epiblast and hypoblast, surrounding a cavity, the archenteron, which opens to the exterior by the orifice of invagination or blastopore.

) A, Blastula stage (one-cell-layered eaten its way into the in sac), with commencing invaginated endodermal sac, vagination of the wall of the and the cells pushed in with sac at bl, the blastopore.

The mesoblast of the cephalic (naupliar) region probably arises in connexion with the lips of the blastopore and consists of loosely-connected cells or mesenchyme.

"It has usually been regarded as representing both endoderm and mesoderm, and the groove which usually leads to its formation has been compared to the abnormally elongated blastopore of a typical gastrula.

C, Diblastula of an Opisthobranch (Polycera) with elongated blastopore oi.

The enteron arises as a space in the endoderm, and an opacity - the primitive streak - appears at the hind end of the blastopore (fig.

The blastopore, together with the whole embryo, now elongates.

They surround a region which is termed the peristome, and which contains in the centre the blastopore, which becomes the adult mouth.

The preconchylian invagination or shell-gland is formed in the embryo behind the velum, on the surface opposite the blastopore.

It has usually been regarded as representing both endoderm and mesoderm, and the groove which usually leads to its formation has been compared to the abnormally elongated blastopore of a typical gastrula.

The blastopore is formed as a secondary perforation at one spot, in free-swimming forms at the hinder pole.

The cavity communicating with the blastopore and lined by the endoderm is the archenteron.

Then the large cells recommence the process of division and sink into the hollow of the sphere, leaving an elongated groove, the blastopore, on the surface.

Synonyms:

orifice, archenteron, porta, opening,

Antonyms:

natural object, finish, closing,