Sinus opening in middle meatus is: September 2011

Ans. C: Frontal Sinus Frontal sinus opens into the middle meatus of the nose at the anterior end of hiatus semilunaris Middle Meatus It is a nasal opening or canal situated between the middle and inferior conchae, and extends from the anterior to the posterior end of the latter. On it is a curved fissure, the hiatus semilunaris and limited below by the edge of the uncinate process of the ethmoid and above by an elevation named the bulla ethmoidalis; the middle ethmoidal cells are contained within this bulla and open on or near to it. Through the hiatus semilunaris the meatus communicates with a curved passage termed the infundibulum, which communicates in front with the anterior ethmoidal cells and in rather more than fifty percent of skulls is continued upward as the frontonasal duct into the frontal air-sinus; when this continuity fails, the frontonasal duct opens directly into the anterior pa of the meatus. Below the bulla ethmoidalis and hidden by the uncinate process of the ethmoid is the opening of the maxillary sinus (ostium maxillare); an accessory opening is frequently present above the posterior pa of the inferior nasal concha.