Findings

This diagram summarizes ovarian structure and follicular development.

Comment

During embryogenesis, there is a massive mitotic division that results in about 6 million germ cells. At birth, only about one-tenth of the original oocytes remain. These are all arrested in the prophase stage of the first meiotic division. At puberty, only about 400,000 follicles are left in the cortex and a small number mature with each menstrual cycle. Of these, usually only one matures into a Graafian follicle and is ovulated. The others undergo atresia.

Specimen

Ovary

Image Credit

Andrew P. Mizisin, Ph.D.
Department of Pathology
School of Medicine
University of California, San Diego

Katsumi M. Miyai, M.D., Ph.D
Department of Pathology
School of Medicine
University of California, San Diego