Structure: Sinuses

Several air-filled cavities, known as sinuses, are situated in the skull bones around the nose and the eyes. The size and shape of these sinuses vary between individuals. Sinuses are not present at birth but gradually develop throughout childhood. They help to lighten the skull bones and give the voice resonance. Within the lining of the sinuses are many mucus-secreting glands. Mucus passes continuously through narrow channels that lead from the sinuses to the back of the nose. The mucus traps small airborne particles and moistens inhaled air as it passes though the airways.

Front view of the sinuses

Sinuses are named after the bones in which they are found. The sinuses in the front of the skull are the frontal and maxillary sinuses.

Side view of the sinuses

The two sphenoid sinuses are situated deep in the skull. In front of them lie the numerous ethmoid sinuses.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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