//the Granulosa Cells

The granulosa cells are believed to originate from ovarian surface epithelial mesothelium or possibly from the rete ovarii.[77] The cohort of granulosa cells that surrounds each oocyte has an oligoclonal origin, with three to five parent cells giving rise to the full complement of granulosa cells in a mature follicle.[78] Granulosa cells receive no direct blood supply, and because a basal lamina separates them from the vascularized theca interna, there is a relative blood– follicle barrier that restricts the entry of leukocytes and high–molecular-weight substances (such as low-density lipoproteins). The absence of a blood supply also necessitates intimate intercellular contact between neighboring granulosa cells and the oocyte.