Developmental Anatomy

Stage 2: Lab Manual - Horizon II Segmenting Ovum

Two Cells

  • 0.1 - 0.2 mm in diameter.
  • Two-cell ovum recovered from the Fallopian tube.
  • Smaller upper polar body between the two blastomeres.
  • Spherical and surrounded by the zona pellucida.
  • The probable ovulation age is 2 - 3 days.

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Developmental Stages in Human Embryos by Ronan O'Rahilly and Fabiola Müller.
Published by Carnegie Institution of Washington, Publication 637. 1987.

Stage 2 (PDF 78 KB)


QUESTION: Where is the upper polar body located?