part_of adult midgut epithelial lining adult peritrophic membrane TADS:0000484 TADS:0000484 The peritrophic membrane is an amorphous, proteinaceous membrane that appears several days after the commencement of feeding. It has been conclusively demonstrated in Ixodes scapularis and is assumed to occur in most, if not all species of ticks. This membrane forms a barrier between the delicate epithelial lining of the midgut and the lumen, making it difficult for invasive microbes to penetrate the midgut. Vol. 2. Fig. 26-7, in Biology of Ticks ISBN:0-19-505910-7. default_namespace acellular anatomical structure