8 secondary follicle: small space appear primary oocyte continuous to develop and reach largest D (125 150um) follicular cell: more layers follicular cavity: space between follicular cells (6-12 layers) /small space-large cavity (filled with follicular fluid)③ secondary follicle: small space appear ---primary oocyte: continuous to develop and reach largest D(125- 150um) ---follicular cell: more layers ---follicular cavity: space between follicular cells (6-12 layers) /small space→large cavity (filled with follicular fluid)