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Related to Blastopore: archenteron


The opening of the archenteron.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(also protostomatic mouth, or gastropore), an opening by means of which the cavity of an animal embryo (in the gastrula stage) interacts with the surrounding environment. In the process of development among some animals (protostomatic), the blastopore becomes a mouth or forms both a mouth and an anal opening; in others (deuterostomatic) an anal opening or nerve intestinal canal is formed in place of the blastopore. This temporarily connects the digestive cavity with the cavity of the nerve tract.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The blastodic became apparent on day 28 and the blastopore was visible on some eggs (Fig.
The blastopore and archenteron were visible in the diminished vegetal half of chlorpyrifos-treated larvae.
In carideans that form a blastoderm, the mesoderm and endoderm rise by subsequent cell ingression and delamination from a small blastopore located at one of the ends of the longest embryo axis.
Stage II ended when the blastopore was closed and the optic cups distinguished head and tail regions of the embryo.
2C), is buoyant and pear-shaped, with a central blastopore. Brachiolariae have two arms in the middle of the larval body (post-oral) and another arm on the pre-oral lobe (Fig.
comprised an ectoderm and endoderm and had a closed blastopore. Each of the thousands of ectodermal cells bore a single cilium on its outer surface (Fig.
The blastopore closed on day 15 when the germ ring completely enveloped the yolk.
The resulting blastopore started as a wide pit, subsequently deepening into the archenteron (Fig.
In Xenopus the epithelium becomes polarized between gastrulation and neurulation; current influx, ranging from 0.1 to several [mu]A/c[m.sup.2], occurs over the entire surface of the embryonic epidermal epithelium; and substantially greater current efflux occurs through the low-resistance path of the blastopore, the opening to the primitive gut (Robinson and Stump, 1984).
During metamorphosis, the larval anus (the derivative of the blastopore) closes, and the larval rectum and intestine undergo resorption.
The zoanthella larva (named by van Beneden, 1897) was first described by Semper (1867); this larva is an almost cylindrical planula that has a long, mid-central ciliary band extending from the blastopore to the anterior pole.
The blastopore remains open throughout gastrulation and is situated initially in the center of the vegetal pole of the embryo (Fig.