Posterior ethmoidal sinus opens into: (A) Superior nasal meatus, (B) Middle nasal meatus, (C) Inferior nasal meatus, (D) Sphenoethmoidal recess
Answer is A. The posterior ethmoidal air sinus consisting of 1-7 air cells open into the superior meatus of the nose. It is supplied by the posterior ethmoidal nerve and vessels and the orbital branches of pterygopalatine ganglion. Ref BDC volume 3,6th edition pg 246