The ciliated cells move the mucus over the sinus membranes in a specific direction, so that the mucous blanket with its trapped particles can be
excreted. These cells each contain between 50 and 200 tiny microscopic hairs called cilia, which move at an astounding rate of close to 800 times a minute. These cilia cells beat like a sweeping broom, pushing the mucus through each of the sinuses from the front of the nose to the back. The back of the nose is called the nasopharynx, because this area connects the nose and the throat (pharynx).
You might think that gravity is pulling the mucus along. However, this is not always the case. For example, the hair cells in the maxillary sinus lift the mucus with its trapped particles along its side walls against gravity. And the hair cells in the frontal sinus sweep in a specific direction as well. The maxillary sinus drains its mucus through an opening located at the top of the sinus, and then into an area called the in - fundibulum. The infundibulum is part of the ostiomeatal complex (OMC), which includes the anterior ethmoid sinuses (7). The OMC is called “the key to the sinuses” because the frontal sinus, the maxillary sinus, and the anterior ethmoid sinuses drain into this area.
When the OMC gets blocked or plugged up, the anterior ethmoids and the frontal and maxillary sinuses have nowhere to drain. The mucous blanket then backs up into the frontal and maxillary sinuses, and these areas become inflamed.