The nasal passages of the lower sections are part of the respiratory and olfactory systems, which are located in the nasopharynx. In turn, the nasal passages are divided into 3 parts: superolateral, posterior and ophthalmic. The nasal cavity, or nose, is the opening between the mouth and nostrils. It is a cavity in the facial part of the skull, communicating with the upper respiratory tract through the choanae - the openings of the skull. The nasal cavity is divided into two longitudinally by the septum and three transversely by slopes; in each of these parts it is located along the side wall of the nasal cavity.