Histogenesis of Irregular Areola During Early, Mid and Late Gestation in Porcine (Sus domesticus)

Abstract

Areolae are specialised areas of placenta for histotrophic nutrition. Sequential development of irregular areolae of
porcine placenta was carried out using specimens from 20 to 105 days of gestation. The tissues were processed for routine
histological techniques. Irregular areola was observed around 28 days of gestation. It comprised of a chorionic wall, an endometrial
wall and an intervening wide areolar cavity. Chorionic wall was relatively smooth and arched over areolar cavity. The tall columnar
lining cells of chorion possessed long microvilli, enclosed abundant vacuoles and dark granules. The endometrial epithelium
revealed festoon like folds and its lining cells presented a feathery nature. The epithelium was lined by tall columnar cells which
enclosed vacuoles and dark granules. The cells also possessed short microvilli. Intense PAS reaction was noticed in the maternal
epithelium. Sub-epithelial capillary network was better developed in the chorionic region. The cellular features suggested that
chorionic cells may have a predominantly absorptive function whereas the uterine epithelium may play a secretory role.