Changes

* Oocyte (the egg which contains the genetic material and gets fertilised)

* Oocyte (the egg which contains the genetic material and gets fertilised)

* Zona pellucida - relatively thick and strong zone of extracellular material protecting the oocyte

* Zona pellucida - relatively thick and strong zone of extracellular material protecting the oocyte

* Granulosa cells (the cells surrounding the egg in a circumferential formation, produce [[estrogen]]

* Granulosa cells (the cells surrounding the egg in a circumferential formation) produce [[estrogen]]

* Antrum (fluid filled cavity in developed follicles which contains liquor follicular)

* Antrum (fluid filled cavity in developed follicles which contains liquor follicular)

* Theca cells (technically not part of follicle, are the cells of the ovary surrounding the follicle which produce androgen)

* Theca cells (technically not part of follicle, are the cells of the ovary surrounding the follicle which produce androgen)