Ovulation

This is the release of mature egg cells (oocyte) from the ovary after the formation of the Graafian follicle (final stage of follicle development before ovulation). Ovulation occurs around the middle of the cycle, around the 14th day of the cycle (normal range – 12-16 days), in a 28-day cycle. Some women may feel mild pain in the lower abdomen during ovulation. During each menstrual cycle, follicles begin to mature, but usually only one of them matures to the Graafian follicle stage. This follicle grows rapidly due to the influence of hormones (follicle-stimulating hormone and luteinizing hormone) and before ovulation, it is about 15 mm in diameter. Ovulation is stimulated by the maximum concentration of luteinizing hormone (regulated by the pituitary gland). The follicle eventually ruptures due to wall pressure and enzymatic processes. During ovulation, the uterine mucosa membrane reaches its maximum size, as do the mucosal glands (although they do not yet secrete). After ovulation, the Graafian follicle becomes the corpus luteum, which starts producing the hormone progesterone. Many natural family planning methods rely on determining the day of ovulation. It is known that starting approximately 3-4 days after ovulation, a woman cannot conceive.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė