What are the changes in the oogonia during the transition of a primary follicle to Graafian follicle?

Changes that occur in the oogonia during the transition of a primary follicle to Graafian follicle are:

1) Germinal epithelial cells divide repeatedly to form multiple diploid oogonia.

2) These oogonia grow to form primary oocyte.

3) These primary oocytes get surrounded by granulosa cells and form a primary follicle

4) Primary oocyte gets surrounded by more granulosa cells and forms a primary follicle.

5) Now this primary follicle, gets surrounded by more granular cells in order to form secondary follicle.

6) This secondary follicle converts into tertiary follicle by adding more granulosa cells.

7) The primary oocyte within the tertiary follicles, undergoes meiotic division in order to form secondary oocyte and a haploid polar body.

8) This tertiary follicle then, matures into graafian follicle which in turn, ruptures to release secondary oocyte or ovum.