The maxillary sinus ostia is bounded from below by uncinate process (U) and above by the lower bony portion of ethmoid sinuses (E). A narrowing in this critical area can cause sinusitis.

The sinuses are lined with ciliated stratified columnar epithelium and are contiguous with the upper respiratory tract via the sinus ostia. Inflammation of the sinuses causes mucosal edema and ...

1 = Upper sinus venosus defect 2 = Lower sinus venosus defect 3 = Ostium secundum atrial septal defect 4 = Coronary sinus atrial septal defect 5 = Ostium Primum atrial septal defect The murmur ...

1 = Upper sinus venosus defect 2 = Lower sinus venosus defect 3 = Ostium secundum atrial septal defect 4 = Coronary sinus atrial septal defect 5 = Ostium Primum atrial septal defect The murmur ...