The germial epithelial cells divide repeatedly until many diploid oogonai are formed. The oogonia grow to form primary oocytes. Each primary follicle. The gets surrounded by a layer of granulosa cells and then called the primary follicle. The primary follicle get surrounded by more layers of granulosa cells and called secondary follicales.
The secondary follicle soon trasforms into a tertiary follicle which is characterised by a meiotic division to become a secondary oocyte and a fisrt polar body (hapliod).
The tertiary follicle furthre changes into the mature follicle or Graaflan folllcle. follicle. The Graafian follicle now ruptures to release to release the secondary oocyte (ovum) from the ovary by the process called ovulation.
