Sinusitis is inflammation of the Sinuses.
Anatomy
We have four sinuses Maxillary, Frontal, Ethmoid & Sphenoid. They are air filled cavities, lined with a mucous membrane.
What are they for?
The sinuses humidify/warm the air before it enters the lungs for gaseous exchange.
They are lined with mucous membrane which produces a slimy secretion called mucus to keep the nasal passageways moist and to trap dirt particles and bacteria.
The sinuses which are lined with cilia waft this unwanted material out of the sinuses and towards either the nasopharynx where it is swallowed or towards the nasal cavity where it is blown out.
What causes Sinusitis? R