What hormonal surge triggers ovulation?

The surge that triggers ovulation is primarily due to luteinizing hormone (LH). In the menstrual cycle, just before ovulation, there is a significant increase in estrogen levels, which stimulates the anterior pituitary gland to release a surge of LH and to a lesser extent, follicle-stimulating hormone (FSH). This LH surge is crucial as it causes the mature follicle to release an egg from the ovary, marking the point of ovulation.

While FSH does play a role in follicular development and maturation, it is the LH surge that is the key trigger for the actual process of ovulation. Estrogen is involved in the lead-up to ovulation, but it is the spike in LH that directly leads to the release of the egg. Progesterone, on the other hand, is produced after ovulation and helps prepare the uterine lining for potential implantation. Antidiuretic hormone (ADH) is involved in water balance in the body and is not directly related to the ovulatory process.

Thus, recognizing the role of LH, particularly its surge, is essential in understanding the hormonal regulation of ovulation.