<prompt> Most of the airway resistance is from:Terminal bronchiolesRespiratory bronchiolesMedium sized bronchiTrachea  <response>: 23 generations of respiratory tree:Trachea 0th generationFurther divisions new generations First 7 generations CartilaginousNon cartilaginousLast 16 generations Non cartilaginousCompressibleThin layer of smooth muscles ntSome neuro endocrine cells ntAPUDKULCHITSKY CELLSFirst 16 generations - Conducting zone dead spaceLast 7 Non cartilaginous Respiratory zoneNote:Out of first 16 generations, trachea 0th generation offers maximum resistance.Reference: GUYTON AND HALL TEXTBOOK OF MEDICAL PHYSIOLOGY, THIRTEENTH EDITIONINTERNATIONAL EDITION 