The larger one at the top is a hemorrhagic corpus luteum of menstruation, and the smaller one at the bottom is involuting from a previous menstrual period.

• 图上方大者为月经期间黄体出血。下方小者为上次月经后形成的退化的黄体。如果卵子受精，黄体便产生雌激素和孕激素，称为妊娠黄体。