| Sinuses are chambers which are located in the bones of the face and skull. They are normally lined with mucosa, a thin mucus-producing membrane. The four pairs of sinuses include the maxillary, ethmoid, frontal, and sphenoid sinuses. The illustration below shows the frontal, ethmoid, and sphenoid sinuses. The maxillary sinuses will be shown in another illustration.
Narrow openings allow the sinuses to communicate with the nasal cavity, passing air and mucus through these openings. If the small sinus openings become blocked, which can occur from infection, allergies, swelling and other causes, sinusitis can occur.
|
Sinus Anatomy
