SkyMark, JetStar and others offer flights from Tokyo and other major cities in Japan to Naha. Low cost airlines such as Air Asia Japan and Peach Aviation now fly between Okinawa (Naha) and Tokyo Narita, Osaka Kansai respectively. Most Japanese airlines do offer deep discounts, but they MUST be bought in advance.
The alveoli are open to the environment so alveolar pressure (i.e. the pressure inside the lungs) is really the same as atmospheric pressure. Intrapleural pressure is the pressure of the air in the pleural cavity in which the lung sits (the space between the lung tissue and the chest wall).
The basic function of alveoli is exchange of gases. Its structure is the site where the gaseous exchange during respiration takes place. These structures are surrounded by capillaries carrying blood. The exchange of carbon dioxide in the blood from these capillaries occurs through the walls of alveolus.