overlaps proventriculus intermediate layer adult midgut epithelium adult foregut epithelium adult proventriculus intermediate layer adult proventriculus recurrent layer FBbt:00047171 intermediate layer of the adult cardia fly_anatomy.ontology recurrent wall of the adult cardia Intermediate layer of the proventriculus (cardia) of the adult. It folds back over the inner layer and contains foregut cells in the posterior part, followed by midgut cells in the anterior part (King, 1988). adult proventriculus epithelium