Multiple choice Which part of a cockroach is lined by the peritrophic membrane? Foregut Midgut Hindgut Salivary glands Reveal answer Fill a bubble to check yourself B Correct answer Explanation Peritrophic membrane lines the wall of midgut. The peritrophic membrane serves several functions, including improvement of digestion, protection against mechanical and chemical damage, and serving as a barrier to infection by pathogens.