The ethmoid sinuses are the key to nasal health. Just as all roads lead to Rome, mucus produced in any of the sinuses is eventually drained through or by the ethmoid sinuses. For example, the mucus produced in
the frontal sinuses drains through the ethmoid sinus by a connection called the frontal duct or frontal recess. The maxillary sinuses drain through an opening called the maxillary ostium. This drains into a funnel-like area called the infundibulum, which is also connected to the ethmoid sinus. From any source, the mucus then passes through the ethmoid sinuses and into the back of the nose.
The front of the ethmoid sinuses sits below the middle turbinate in the middle meatus. The back of the ethmoids sit below the superior turbinate in the superior meatus. The middle turbinate attaches to the outside wall of the sinus, which also serves as the inside wall of the eye. The wall that is created by this attachment is called the ground lamella and separates the anterior and the posterior ethmoid sinus cells.
The ethmoid sinuses are shaped like a beehive and are composed of approximately 22 smaller cavities or cells. Each cavity increases the surface area so that the air can be quickly heated, vaporized, humidified, and filtered as it passes over the mucous blanket that coats the ethmoid sinuses.