gastrula

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gastrula

 [gas´troo-lah]
an embryo in the stage following the blastula stage; the simplest type consists of two layers of cells, the ectoderm and entoderm, which have invaginated to form the archenteron and an opening, the blastopore.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

gas·tru·la

(gas'trū-lă),
The embryo in the stage of development following the blastula or blastocyst; in lower forms with minimal yolk, it is a simple double-layered structure consisting of ectoderm and endoderm enclosing the archenteron, which opens to the outside by way of the blastopore; in forms with considerable yolk, the configuration of the gastrula is greatly modified owing to the persistence of the yolk throughout the gastrulation process. In human embryos, the gastrula stage occurs in the third week as the embryonic disk becomes trilaminar.
Synonym(s): invaginate planula
[Mod. L. dim. of G. gastēr, belly]
Farlex Partner Medical Dictionary © Farlex 2012

gastrula

(găs′trə-lə)
n. pl. gastru·las or gastru·lae (-lē′)
An embryo at the stage following the blastula, after the movement of cells results in the formation of the three germ layers, ectoderm, mesoderm, and endoderm.

gas′tru·lar (-lər) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

gas·tru·la

(gas'trū-lă)
The embryo in the stage of development following the blastula or blastocyst formation; in the human embryo, the absence of yolk allows for a rapid, direct "putting in place" of the germ layers (ectoderm and endoderm), which are derived from the pluripotential embryonic disc.
[Mod. L. dim. of G. gastēr, belly]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

gastrula

The stage in the development of an EMBRYO following the BLASTULA stage when the ECTODERM, ENDODERM and primitive GUT have developed.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

gastrula

a stage in embryonic development in which the BLASTULA has invaginated, so giving rise to a two-layered embryo by a process of gastrulation. see ARCHENTERON.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005