Moulds can be of a single cavity or multiple cavities. This excites the air contained in the usually cylindrical resonant cavity within the flute. The paranasal sinuses surround and drain into the nasal cavity. Connective tissue exists in place of the pleural cavity. However, the main circulatory fluid fills the general body cavity, or coelom. Pericardial recesses are small spaces in the pericardial cavity. Venom is injected into the abdominal cavity. Chronic rhinitis associated with polyps in the nasal cavity. The lungs sit in the pleural cavity. Giant squid breathe using two large gills inside the mantle cavity. It is more commonly associated to infection from a punctured organ of the abdominal cavity. It then passes along the floor of the nasal cavity. If the infection spreads to the lining of the abdominal cavity (the peritoneum), peritonitis results. It separates the oral cavity from the nasal cavity. The mouth leads into a central stomach cavity.