GASTRULA - 8 definitions found
gastrula n 1: double-walled stage of the embryo resulting from invagination of the blastula; the outer layer of cells is the ectoderm and the inner layer differentiates into the mesoderm and endoderm gastrula stragula Merriam-Webster's Collegiate Dictionary, 11th Edition (2003) gastrula noun (plural -las or gastrulae) Etymology: New Latin, from gastr- Date: 1876 an early metazoan embryo in which the ectoderm, mesoderm, and endoderm are established either by invagination of the blastula (as in fish and amphibians) to form a multilayered cellular cup with a blastopore opening into the archenteron or by differentiation of the blastodisc (as in reptiles, birds, and mammals) and inward cellular migration — compare blastula, morula • gastrular adjective Oxford English Reference Dictionary
English Explanatory Dictionary gastrula n. (pl. gastrulae) Zool. an embryonic stage developing from the blastula. [mod.L f. Gk gaster gast(e)ros belly] Webster's Revised Unabridged Dictionary (1913) Stomapoda \Sto*map"o*da\, n. pl. [NL. See Stoma, and -poda.] (Zo["o]l.) An order of Crustacea including the squillas. The maxillipeds are leglike in form, and the large claws are comblike. They have a large and elongated abdomen, which contains a part of the stomach and heart; the abdominal appendages are large, and bear the gills. Called also Gastrula, Stomatopoda, and Squilloidea. Webster's Revised Unabridged Dictionary (1913) Planula \Plan"u*la\, n.; pl. Planul[ae]. [L., a little plane.] 1. (Biol.) In embryonic development, a vesicle filled with fluid, formed from the morula by the divergence of its cells in such a manner as to give rise to a central space, around which the cells arrange themselves as an envelope; an embryonic form intermediate between the morula and gastrula. Sometimes used as synonymous with gastrula. Webster's Revised Unabridged Dictionary (1913) Gastrula \Gas"tru*la\, n.; pl. Gastrul[ae][NL., dim. fr. Gr. ? the stomach.] (Biol.) An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastr[ae]a. -- a. Of or pertaining to a gastrula. |
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