how can we differentiate different types of follicles ie primary,secondary and tertiary.what are their distinctive features??

Hi Sheeba,

Thank you for asking

-In Primary follicle the ova is surrounded by a single layer of epithellium. It develops just after attaining puberty.

-A secondary follicle is a preantral follicle with 2 to 10 layers of cuboidal or low columnar cells that form a stratified epithelium.
-Tertiary Follicle:When a preantral follicle completes the secondary stage in development, it contains five distinct structural units: a fully grown oocyte surrounded by a zona pellucida, six to nine layers of granulosa cells, a basal lamina, a theca interna, and a theca externa

Secondary folicle can be differentiated by more layer of thica granulosa and tertiary by antrum with liquor fluid.