Anatomy

Ovum Cleavage Stage

The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

The earliest developmental stage of a fertilized ovum (ZYGOTE) during which there are several mitotic divisions within the ZONA PELLUCIDA. Each cleavage or segmentation yields two BLASTOMERES of about half size of the parent cell. This cleavage stage generally covers the period up to 16-cell MORULA.

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Classification

Broader headings

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See Also

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Synonyms

7 entry terms
  • Cleavage Stage, Ovum
  • Segmentation Stage, Ovum
  • Cleavage Stages, Ovum
  • Ovum Cleavage Stages
  • Ovum Segmentation Stage
  • Ovum Segmentation Stages
  • Segmentation Stages, Ovum

MeSH Record

Aspects Covered

15 allowable subheadings

Indexed with the subheadings chemistry, classification, cytology, drug effects, enzymology, immunology, metabolism, microbiology, parasitology, pathology, physiology, radiation effects, transplantation, ultrastructure, virology.

MeSH Record

History Note

80

MeSH Record

Previous Indexing

  • Cell Division (1966-1979)
  • Mitosis (1968-1979)
  • Ovum (1966-1979)
  • Zygote (1975-1979)

MeSH Hierarchy

Tree Number

  1. A16.166

AMA Style

References

  1. National Library of Medicine. Ovum Cleavage Stage. Medical Subject Headings (MeSH). 2026. Unique ID D002970. http://id.nlm.nih.gov/mesh/2026/D002970
  2. Ovum Cleavage Stage. In: Wikidata. https://www.wikidata.org/wiki/Q70218086