<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> The corpus luteum (Latin for "yellow body"; plural corpora lutea) is a temporary endocrine structure in female ovaries and is involved in the production of relatively high levels of progesterone, moderate levels of estradiol, inhibin A and small amounts of estrogen . It is the remains of the ovarian follicle that has released a mature ovum during a previous ovulation . It is colored as a result of concentrating carotenoids (including lutein) from the diet and secretes a moderate amount of estrogen to inhibit further release of gonadotropin - releasing hormone (GnRH) and thus secretion of luteinizing hormone (LH) and follicle - stimulating hormone (FSH). A new corpus luteum develops with each menstrual cycle . </P> <P> The corpus luteum develops from an ovarian follicle during the luteal phase of the menstrual cycle or oestrous cycle, following the release of a secondary oocyte from the follicle during ovulation . The follicle first forms a corpus hemorrhagicum before it becomes a corpus luteum, but the term refers to the visible collection of blood, left after rupture of the follicle, that secretes progesterone . While the oocyte (later the zygote if fertilization occurs) traverses the Fallopian tube into the uterus, the corpus luteum remains in the ovary . </P> <P> The corpus luteum is typically very large relative to the size of the ovary; in humans, the size of the structure ranges from under 2 cm to 5 cm in diameter . </P>

What hormone keeps the lining thick once the ovum has been released