月经周期激素和变化，动画

on of the uterus and ovaries showing the changes that occur over the 28 days of the menstrual cycle. The levels of four hormones are shown at bottom left: follicle stimulating hormone (FSH, light blue), luteinising hormone (LH, pink), oestrogen (O, purple) and progesterone (P, yellow). The cycle begins with menstruation (a period), during which the thick lining of the uterus is shed through the cervix and vagina. After this, rising levels of oestrogen promote redevelopment of the lining. In the ovary, fast-rising levels of LH stimulate ovulation, the release of an ovum (pink), at day 14. This travels down the fallopian tube to the uterus. If it is not fertilised it degenerates within a day or so. The remaining part of the ovum's follicle in the ovary develops into a large yellow corpus luteum, which produces large amounts of progesterone. This in turn promotes new production of oestrogen, and inhibits LH and FSH production. Without LH and FSH the corpus luteum degenrates, and falling levels of progesterone and oestrogen lead to the spiral arteries in the endometrium atrophying, and the lining is shed at the start of the next cycle

光厂(VJshi)视频提供月经周期激素和变化，动画视频素材下载，适用于生物学，图表，有月经，受精卵，血液等主题的内容创作。

作者署名：Science Photo Library/Getty Images/华夏视觉