Interior architectural structures and lighting for aircraft, particularly commercial passenger airplanes. Light diffusers and ceiling panels in a "wing-shape" and other secondary panels are utilized to create different interior designs and structures. A permeable secondary panel is utilized in one passenger cabin in order to provide a more private-type space. An enlarged ceiling arch with blended curves forming a "wing-type" configuration provides a more spacious cabin arrangement. Other features include air and light diffusers, passenger service modules, a "shelf"-like configuration and lighting above the airplane entrance/exit door, and bulkheads and monuments positioned at various positions in the cabin.