Neuroendocrine cells in the lungs are:: (A) Dendritic cells, (B) Type I pneumocytes, (C) Type II pneumocytes, (D) APUD cells
Answer is D. APUD (amine precursor uptake and decarboxylation) cells are neuroendocrine cells found in respiratory system, G.I. tract and other organs; they manufactrure amines (e.g. 5-HT). These cells form carcinoid tumors.