Process of Oogenesis
The process of oogenesis takes place in three steps:
Pre-natal stage
In the process of fetal development, germinal epithelium in the ovary grows much larger than others and divides to form egg mother cells or oogonia. After birth, oogonia continues to divide and develop into primary oocytes. These are covered by granulosa cells to create primary follicles. Before puberty, many follicles degenerate, leaving only around 60,000-80,000 primary follicles in each ovary.
Antral stage
The antral stage of oogenesis involves the formation of the antrum, a fluid-filled cavity, within the primary follicle. It marks the transition from a primary oocyte to a secondary oocyte, which is arrested in metaphase II. This stage leads to the eventual release of a mature ovum during ovulation, ready for fertilization.
Pre-ovulatory stage
Two maturation divisions occur in each primary oocyte; the first and second meiotic division. In the first meiotic division, the primary oocyte divides into two haploid daughter cells, one of which is a larger secondary oocyte and the other a smaller first polar body. In the second meiotic division, the secondary oocyte further divides, forming two more haploid daughter cells, one of which is a larger ootid and the other a smaller second polar body. Eventually, the ootid develops into a haploid ovum, while the three polar bodies degenerate. The ovum is the main female gamete involved in reproduction.
What is Oogenesis?
Oogenesis is the process that describes how a mature egg in females develops. Oogenesis is part of a very important process called gametogenesis. Oogenesis helps to ensure that the human species keeps on continuing on the face of the Earth. Oogenesis describes the remarkable journey an oocyte undergoes after it originates from the primordial germ cell. The whole intricate process of oogenesis takes place in the ovarian follicles present in the ovaries. Understanding the process of oogenesis helps us to comprehend female fertility, the menstrual cycle, and female reproductive health.
Table of Content
- What is Gametogenesis?
- What is Oogenesis?
- Process of Oogenesis
- Phases of Oogenesis
- Ovulation
- Oogenesis in Non-Human Mammals
- Ovarian Aging
- Hormonal Control of Oogenesis
- Significance of Oogenesis
- Oogenesis Timeline and Stages
- FAQs – What is Oogenesis?