Jyotsna A. Mahaley, Shantaj M. Deshbhratar, Sonali R. Raut and D. A. Bhiwgade
Present investigations of the interhaemal membrane of thyropterid bat, Tylonycteris pachypus, at an electron microscopic level through the different stages of development have been observed. At the early stages of gestation, distinct maternal endothelium is distinctly observed along with compactly arranged cytotrophoblastic layers followed by syncytiotrophoblast. At this stage of development, cytotrophoblastic layer bears spongy rough endoplasmic reticulum and well developed concentrically arranged Golgi Complexes in few numbers. The maternal endothelium is absent at mid and term stage of placenta. The enclosed lacunae of the maternal blood space comes in direct contact with syncytiotrophoblast i.e. ectoplasmic layer followed by discontinuous intrasyncytial lamina in the syncytiotrophoblast. The syncytiotrophoblast appears spongy due to the presence of modified vesiculated rough endoplasmic reticulum. The cytotrophoblastic basal lamina displays modified podocytic specialization with few desmosomal connections. Glycogen rosettes at the periphery are commonly seen in both the trophoblastic layers. At places there is a considerable attenutation of both layers into thin phalanges, bringing the maternal blood space and foetal capillary closer thereby minimising the thickness of the interhaemal barrier. Absence of maternal endothelium and presence of both the trophoblastic layers at term designates the placenta to be haemodichorial that has been holistically discussed in these contents.
