<prompt> True about sphenoid sinus: PGI May 2010Lined by stratified squamous epitheliumDuct open in middle meatusOpen in sphenoethmoid recessPresent at birth  <response>: Ans: C Open in sphenoethmoid recess The paranasal air sinuses are lined with respiratory epithelium ciliated pseudostratified columnar epithelium- rbinologic. orgypatientLnfo.sinusnasalanatomyphtrnlAnatomy of PNS EL Dhingra 5th201Anterior group: This includes maxillary, frontal and anterior ethmoidal. They all open in the middle meatus and their ostia lie anterior to basal lamella of middle turbinate.Posterior groups: This includes posterior ethmoidal sinuses which open in the superior meatus, and the sphenoid sinus which open in sphenoethmoidal recess.Table These occupy the body ofthe sphenoid boneTrue growth of the sin us occu rs at pubertyZ: 