Eggbildningen

Eggbildningen, also known as oogenesis, is the process by which female gametes, or ova (eggs), are produced in the ovaries. This complex biological process begins before birth and continues throughout a woman's reproductive years. In the fetal stage, immature germ cells called oogonia undergo mitosis to multiply. These oogonia then enter meiosis and arrest in prophase I, becoming primary oocytes.

At puberty, the hormonal cycle triggers the development of primary oocytes. Typically, one primary oocyte per menstrual cycle matures and completes meiosis I, resulting in a large secondary oocyte and a small polar body. This secondary oocyte then begins meiosis II, but it arrests again at metaphase II.

Ovulation occurs when the mature secondary oocyte is released from the ovary. Fertilization by a sperm cell is required to complete meiosis II. If fertilization occurs, the secondary oocyte will divide into a mature ovum and another polar body. If fertilization does not occur, the secondary oocyte degenerates. The polar bodies are non-functional cells that will also degenerate. Eggbildningen is crucial for sexual reproduction, ensuring the production of viable eggs for potential fertilization.