similarly , since available evidence strongly suggests that teratogenic agents induce perturbations in the cellular mechanisms that control these several functions of the yolk-sac placental system in the production of birth defects , additionally an account is given of the cell biology of the membrane , i.e. , endocytosis and targeting/trafficking of materials either for digestion within the epithelium at the maternal surface of the visceral yolk sac or for translocation across the yolk-sac membrane as a whole .
C0007634
cellular
C0014139
endocytosis