part of part of Homo sapiens ethmoid bone zone of bone organ ethmoidal bulla of ethmoid bone 2026-03-19T00:00:00Z A zone of bone organ forming the largest and most prominent of the anterior ethmoidal air cells, which bulges into the middle meatus of the nasal cavity lateral to the middle nasal concha and superior to the semilunar hiatus. David Osumi-Sutherland