The superior meatus, the smallest of the three meatuses of the nose, occupies the middle third of the lateral wall of the nasal cavity. It lies between the superior nasal conchC& and middle nasal conchC&; the sphenopalatine foramen opens into it behind, and the posterior ethmoidal cells in front. The sphenoidal sinus opens into a recess, the sphenoethmoidal recess, which is placed above and behind the superior concha.