Vascular pattern of the mammalian ovary with special reference to the three-dimensional architecture of the spiral artery.

Casts of blood vessels in the ovaries of the female rat, pig and monkey were made with methacrylate, dissected out under a dissecting microscope and observed in a scanning electron microscope (SEM). The ovarian arteries and their branches were characterized by the presence of a spiral configuration. The spiral course of the arteries, however, varied greatly in detail among the different species. The arteries in the pig and monkey ovaries had tightly spiraling configurations, while there was only an image suggestive of a spiral in the rat ovarian arteries. The former species showed a rich plexus of the spiral arteries in the hilus and medulla of the organ. Their branches straightened at the transitional region between the medulla and cortex but again showed spiral configurations in the cortex. Further, the arterial branches supplying the growing and mature follicles showed a much more marked extent to the spiral configurations as compared with those of the corpus luteum. In this paper morphological findings shall be discussed in correlation with their physiological implications.