The development of an ovarian follicle occurs in several stages, which are collectively known as folliculogenesis. This process is regulated by various hormones, including follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The stages of folliculogenesis include:
Primordial Follicle: The initial stage where the follicle consists of an oocyte surrounded by a single layer of granulosa cells. Primary Follicle: The granulosa cells proliferate, and the oocyte begins to grow. Secondary Follicle: The follicle further enlarges, and additional layers of granulosa cells form. A fluid-filled cavity called the antrum starts to develop. Tertiary or Antral Follicle: The antrum becomes more prominent, and the follicle reaches a larger size. The oocyte is now surrounded by the cumulus oophorus, a cluster of cells that support its development. Graafian Follicle: The final mature stage, characterized by a large antrum and readiness for ovulation.
