Histogenesis of Regular Areolae in Porcine (Sus domesticus)

Abstract

Areolae of placenta are specialised regions for histotrophic nutrition. Histogenesis of areolae during porcine gestation
was studied using specimens collected from 20 to 105 days of gestation and representative tissue pieces were processed for
routine histological techniques. Regular areolae appeared grossly from around 25 days of gestation. Histologically, areolae
comprised of achorionic wall, an endometrial wall and an areolar cavity. Chorionic wall presented numerous folds and invaginations and its structural complexity enhanced asgestation progress. This in turnamplified the size as well as surface area of areolae.The lining simple columnar cells of this wall enclosed vesicles, vacuoles and PAS granules. Endometrial wall was linedby simple cuboidal cells and revealed openings of subepithelial endometrial glands. Secretion enclosed in the areolar cavity contained numerous vacuoles and granules.Vascular net-work was poorly developed in areolar regions than the adjacent interareolar areas of placenta. These histological features were supportive of histotrophic type of nutrition of areola.