Corpus luteum, recent.

This is a low power micrograph of an ovary which contains a recently formed corpus luteum. The Graafian follicle, prior to ovulation, is a very large structure and takes up a considerable amount of space in the ovary. After the follicle ruptured in ovulation, it collapsed upon itself and became the corpus luteum. This is the structure which takes up more than half of the ovary here. Compare the size of the corpus luteum with the developing follicles which appear as little white circles beneath the surface of the ovary. The antrum may contain some blood or fibrin. The granulosa cells and theca cells proliferate and increase greatly in size. Blood vessels penetrate the basal lamina of the ruptured follicle and proliferate, turning the corpus luteum into a highly vascularized organ. The granulosa cells become granulosa lutein cells and the theca interna cells become thecal lutein cells. Progesterone, estrogen and relaxin are produced by the corpus luteum. PK4799-34. Original mag. 5x. H&E Corpus luteum. Cortex. Ovary. Female Reproductive System. Cat