blastopore


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Related to blastopore: archenteron

blastopore

 [blas´to-por]
the opening of the archenteron to the exterior of the embryo at the gastrula stage.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

blas·to·pore

(blas'tō-pōr),
The opening into the archenteron formed by invagination of the blastula to form a gastrula.
Synonym(s): protostoma, protostome
[blasto- + G. poros, opening]
Farlex Partner Medical Dictionary © Farlex 2012

blastopore

(blăs′tə-pôr′)
n. Embryology
The opening of the archenteron.

blas′to·por′al, blas′to·por′ic adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

blastopore

The opening of the archenteron, the primitive gut, to the outside, formed by invagination of cells on the embryo’s surface which form the mesoderm and endoderm during during gastrulation.

In some animals, the blastopore becomes the anus; in others, it closes and the anus opens at or near the same site; in some animals (e.g., chickens), invagination gives rise to a virtual blastopore at the primitive streak.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

blas·to·pore

(blas'tō-pōr)
The opening into the archenteron formed by invagination of the blastula (e.g., amphibians) to form a gastrula.
[blasto- + G. poros, opening]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

blastopore

the opening of the GASTRULA.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
References in periodicals archive ?
One week after blastopore closure (day 22), the tail region began lifting away from the yolk, and within two days, the length of the embryo was 50% of the circumference of the yolk.
fuscus appear similar to those of Crepidula fornicata undergoing gastrulation by epiboly, we are uncertain of the origin or consequence of the cellular extensions covering the blastopore on the ventral surface of the late gastrula stage and cannot entirely rule out the combination of epiboly with other known methods of gastrulation (Verdonk and Biggelaar, 1983).
As mentioned above, the embryonic epidermal epithelium forms early in Xenopus development, and the current flow generated through the embryo by the electrical potential across the epithelium exits the blastopore (Robinson and Stump, 1984; Hotary and Robinson, 1994).
At 12 h after spawning, embryos were roughly spherical, with a blastopore (Fig.
Our conclusion, based on the location of the chaetal sac, the folding of the archenteron, and the relative locations of the stomodeum, anus, and chaetal sac in the earliest swimming larval stage, is that the blastopore becomes the opening immediately adjacent to the chaetal sac in the larva and thus forms the anus.
As the blastopore closes, the immunoreactive cells are localized to the stomadeum cells that give rise to the foregut structures such as the mouth and anterior region of the esophagus, as shown in C.
Haeckel (1874) suggested that the eumetazoan ancestor was a gastraea with ectoderm, endoderm, and archenteron with blastopore, essentially having the same structure as that of larval and adult cnidarians and of ontogenetic stages of many bilaterians.
Development of hoplonemerteans, superficially similar to that of palaeonemerteans, is fundamentally different in the fate of larval epidermal cells and blastopore, and in other morphogenetic events.
Early gastrulae show an enlarged blastopore whose aperture progressively reduces in older gastrulae (compare Fig.
The blastopore developed at the middle of the dark cytoplasm, about 24 h post-fertilization, and its rim was marked by dark pigment (Fig.
1H, 2C), with the blastomeres aggregated, at first, around the blastopore. Gastrulation led to the formation of an embryo with two cell layers encompassing a central cavity--the archenteron (Figs.
In both species, spiral cleavage and gastrulation by epiboly result in a very slightly flattened gastrula with a central blastopore. In C.