Ovarian follicle

Ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It also secretes hormones that influence stages of the menstrual cycle. Women begin puberty with about 400,000 follicles, each with the potential to release an egg cell (ovum) at ovulation for fertilization. These eggs are developed only once every menstrual cycle.

Structure

Ovarian follicles are the basic units of female reproductive biology. Each of them contains a single oocyte (immature ovum or egg cell). These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. They also consists of granulosa cells and theca of follicle.

Oocyte

Once a month, one of the ovaries releases a mature egg (ovum), known as an oocyte. A follicle is an anatomical structure in which the primary oocyte develops. The nucleus of such an oocyte is called a germinal vesicle (see picture).

Cumulus oophorus

Cumulus oophorus is a cluster of cells (called cumulus cells) that surround the oocyte both in the ovarian follicle and after ovulation.