The female reproductive system includes the ovaries, fallopian tubes, uterus, vagina, vulva, mammary glands and breasts. These organs are involved in the production and transportation of gametes and the production of sex hormones. The female reproductive system also facilitates the fertilization of ova by sperm and supports the development of offspring during pregnancy and infancy. Ovary has outer cortex and inner medulla. Cortex has follicles of different stages of oogenesis, which are primary follicle, secondary follicle, graafian follicle, corpus luteum and corpus albicans. The ovum is covered by a homogeneous membrane, the zona pellucida.