Uterous

The uterus has three major functions: to prepare a bed for a fertilized ovum, to nourish the developing embryo during pregnancy, and to expel the fetus. Shaped like an upside-down pear, and tilted forwards, it lies within the pelvis and is held in place, along with its two extensions, the Fallopian tubes, by ligaments and folds of the peritoneum. The cervix forms the lower third, connected by a narrow isthmus to the main muscular body of the uterus. The non-pregnant uterus weighs 45–60 g and is 7–8 cm long but its weight increases more than ten-fold by the end of pregnancy.

Corpus luteum

The corpus luteum is what is left of the follicle after a woman ovulates. During the follicular phase of a woman’s cycle, several follicles develop under the influence of FSH (follicle stimulating hormone). Each follicle contains an egg. In a typical cycle only one egg will become mature enough for ovulation. When a woman ovulates the egg will burst from the follicle. Then what is left of the follicle will become the corpus luteum. The luteal phase, named after the corpus luteum, is the second half of a woman’s menstrual cycle. The luteal phase begins after ovulation and continues until menstruation occurs.