Menstrual cycle. Artwork of a woman's monthly men- strual cycle, showing the thickness of the uterus lining (endometrium, blue) as a graph. For the first few days the endometrium breaks up & is shed. This causes bleeding known as a menstrual period. The heaviness of the menstrual period over time is shown by the blue drops at top left. After menstruation the endometrium thickens in readiness for ovulation at day 14. At ovulation the woman's ovaries release an egg (top centre). If the egg becomes fertilised over the next few days it will attach itself to the uterus & pregnancy ensues. If not the menstrual cycle will begin again. The menstrual cycle is controlled by female hormones.
Model release not required. Property release not required.