Ovarian follicles are spherical cell aggregations within the ovary containing an ovum. During ovulation, an egg is released from the ovarian follicle. The ovarian follicle is made up of several parts. These parts include an external fibro-vascular coat, an internal coat of nucleated cells, and a transparent, albuminous fluid in which the ovum is suspended. The growth of the ovarian follicle is initiated by the follicle stimulating hormone (FSH). The ovarian follicle is an important part of the woman's reproductive system.