Library · Anatomy
Paranasal sinuses
Make it clearer
The bones of your face and of the base of your skull are not solid. Inside them are hollow spaces filled with air, and those spaces are called the paranasal sinuses. They are air bubbles trapped inside a block of stone. They come in four pairs: the maxillary sinuses, the largest ones, which sit below the eyes; the frontal sinuses, above the eyes; the ethmoid sinuses, a group of small air cells between the nose and the eyes; and the sphenoid sinuses, farther back, in the center of the head.
What exactly they are for is still debated, and that is worth saying plainly. What they are credited with is lightening the weight of the skull, giving the voice resonance, cushioning blows to the face, insulating delicate structures from sudden changes in temperature, and helping warm and humidify the air you breathe.
What is clear is that none of them is a closed room: they all empty into the nose. The frontal sinuses, the front ethmoid cells, and the maxillary sinuses drain through a passage called the middle meatus, and the sphenoid sinuses and the back ethmoid cells drain through the superior meatus.
In brief
They are four pairs of cavities hollowed out of bone: the maxillary, frontal, ethmoid, and sphenoid sinuses.
Air bubbles trapped inside a stone.
Their function is debated; they are credited with lightening the skull, adding resonance to the voice, cushioning blows, insulating sensitive structures, and helping warm and humidify the air.
They all drain into the nose: the frontal, anterior ethmoid, and maxillary sinuses into the middle meatus, and the sphenoid and posterior ethmoid sinuses into the superior meatus.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingAnatomy, Head and Neck, Nose Paranasal Sinuses, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated