Fig. 2

Photomicrographs of different ovarian follicles in control and PCOS rats. a Primordial follicle with flattened layer of granulosa cells (GC) at (× 40) with oocyte (O) b Primary follicle with cuboidal layer of granulosa cells (GC) and a well-defined oocyte (O) at (× 40) c Secondary follicle with 2-3 layers of granulosa cells (GC), follicular fluid and a prominent oocyte (O) at (× 40) d A tertiary follicle with clear antrum (A), thick granulosa cell layer (GC) surrounded by theca (T) layers at (× 20) e A graffian follicle with a large antrum (A), a primary oocyte (O) surrounded by zona pellucida (ZP) and corona radiate (CR) and thick graulosa layer along with theca layer (T) at (× 20) (f) A cystic follicle with large antrum (A) lacking oocyte and decreased granulosa layer (GC)