blastula

blas·tu·la  (blsch-l)

n. pl. blas·tu·las or blas·tu·lae (-l)

An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity. Also called blastosphere.

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[New Latin : from Greek blastos, bud + Latin -ula, feminine diminutive suffix.]

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blastu·lar adj.

blastu·lation (-lshn) n.

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blastula  (blsch-l)

Plural blastulas or blastulae (blsch-l)

An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity known as a blastocoel. Compare gastrula. See also blastocyst.

Thesaurus

Noun

1.

blastula - early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs blastosphere conceptus, fertilized egg, embryo - an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life blastocele, blastocoel, blastocoele, cleavage cavity, segmentation cavity - the fluid-filled cavity inside a blastula blastocyst, blastodermic vessicle - the blastula of a placental mammal in which some differentiation of cells has occurred trophoblast - the membrane that forms the wall of the blastocyst in early development; aids implantation in the uterine wall; "after implantation of the blastocyst in the uterine wall the trophoblast divides into two layers, the chorion and the placenta"