Inside the nose and sinuses
Follow mucus from the nasal passages to the throat, then locate the four groups of sinuses.
Direction only; speed is illustrative.
Anatomy: BruceBlaus, CC BY-SA 4.0. Highlight and clearance path added. Image credits
Four groups of sinuses surround the nose
These air-filled spaces connect to the nasal cavity. They are not one large open chamber.
- Frontal
- Above the eyes, in the forehead.
- Ethmoid
- Small air cells between the eyes.
- Sphenoid
- Deep behind the nose and ethmoid cells.
- Maxillary
- In the cheekbones, beside the nose.
Red shading in this illustration represents inflammation.
Sources: Nasal physiology · Nasal conchae · How nasal congestion develops