Question

How many primordial follicles are there before birth and then at birth, puberty and menopause? What happens to most of the follicles? (50 words or less)

Answer 1

Approximately 400,000 follicles remain out of 6-7million that were present midway[20 weeks]through gestation.At birth,the ovary contains around 400000 primordial follicles which contain primay oocytes. In each ovarian cycle,about 20 primordial follicles are activated to begin maturation.however, normally only one follicle matures,and the rest contribute to the endocrine function of the ovary,when activated ,the first meiotic division is completed.Near 1000 follicles was used for the occurrence of menopause,assuming a mean age at menopause of 51 years.A number of follicles set around the time of birth,renewal of ovarian follicles from germline stem cells was reported in the postnatal mouse ovary.but a study of populations in 325 human ovaries found no supporting evidence for follicular replenishment.The time women are 30 years old,only 10%of their non growing follicles remain.At birth,women have all their follicles for folliculogenesis, and they steadily decline until menopause.