Ovarian Follicles
Ovarian follicles contain a single oocyte (immature ovum or egg). These eggs/ova are developed only once every menstrual cycle. A woman begins puberty with about 400,000 follicles.
Part of: Ovaries
See also: How the Menstrual Cycle Works
About Ovarian Follicles
According to present knowledge, ovaries already contain all the egg cells women will have in their lifetime when they are born. These egg cells lie in small pockets called follicles. Once puberty starts, different hormones cause the first follicle to mature and release an egg cell (ovum).
Hormones are substances produced by the body that act as chemical transmitters. They regulate body functions like the menstrual cycle and body temperature. Hormones also trigger ovulation.
What happens during ovulation?
Around the time when a mature egg cell has left the ovary, a woman can get pregnant. The egg cell travels down the fallopian tube into the uterus. The moment the egg cell leaves the ovary is called ovulation. Once a girl has had her first monthly period, ovulation usually occurs once a month. Institute for Quality and Efficiency in Health Care (IQWiG)