Germinal disc

Germinal disc may refer to:

In birds

The germinal disc, also called the blastodisc, is a small, circular, white spot (approximately 1.5-3 mm across) on the surface of the yellow yolk of a bird's egg.

In mammals

The blastodisc is a round single-cell layer of cells inside the blastula from which the embryo is going to form. The blastodisc is composed of two layers: hypoblast and epiblast. The hypoblast layer lies adjacent to the blastocyst cavity and is composed of small, cuboidal cells. The epiblast layer, composed of a layer of columnar cells, is adjacent to the amniotic cavity.[1]

References

McKinley, Michael P. (2020). Human anatomy. O'Loughlin, Valerie Dean,, Pennefather-O'Brien, Elizabeth (Sixth ed.). New York, NY. ISBN 978-1-260-25135-7. OCLC 1097366721.

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[1] McKinley, Michael P. (2020). Human anatomy. O'Loughlin, Valerie Dean,, Pennefather-O'Brien, Elizabeth (Sixth ed.). New York, NY. ISBN 978-1-260-25135-7. OCLC 1097366721.