Most of us suffer or have suffered from allergies, sinus infections, the common cold, and various other sinus problems at some point. Even with all of the possible difficulties in that area, however, many people have no idea what is really going on up there – so here is a basic explanation of those sometimes pesky, but very important, cavities.
Located in your head, near the front of your face by the nose, the paranasal sinuses are an interconnected set of cavities. Aside from their respiratory functions and improving the resonation of our voices, these four pairs of air-filled pockets actually help to lighten your skull, making it easier for us to carry our big heads around. The largest pair, about 1 inch across in adults, is found in the cheekbones; the other, smaller sets are located between the eyes, behind the nasal cavity, and in the center of the forehead. These pockets grow with us, starting at the size of a pea in infants and reaching full size after puberty, although the size varies from person to person.
The sinuses are, of course, most commonly associated with the nose. The two are connected by the ostium, the opening of each cavity into the nose: from here, the sinuses drain through a small pathway called the middle meatus. The nose itself is divided by a thin wall called the septum; some people have a deviated septum, which blocks airflow through the nose.
The sinuses are lined with tissue that produces mucus, which, in a healthy sinus cavity, serves to catch dust, dirt, allergens, and other pollutants that we breathe in. Aside from this filtering, it also humidifies the air we breathe, moisturizing the inside of our nose. Cilia, tiny hairlike structures on the lining, slowly and regularly sweep the mucus secretions back into the nose, where they are eventually disposed of by swallowing.
When the sinuses are infected – by a viral or bacterial infection, for instance – more mucus is produced and the lining of the cavities swell, which prevents proper draining. Because the sinuses are so closely linked to the nose, ears, and throat, infections and other issues in this area can seem to affect our whole head, and cause a number of uncomfortable problems.