Sinuses are air-filled pockets within the anatomy of the face.

Generally, these air pockets are located around the nose, which is why we feel facial pressure in that area when we are experiencing sinus congestion. These sinuses are made up of four sets of two and if their names sound familiar, it is because they are correlated with the facial bone that they are associated with.

  • The first set are the maxillary sinuses, which are located in the cheek bones under the eyes.
  • The frontal sinuses extend from above the nose to above the eyes behind the forehead.
  • Next are the ethmoid sinuses, which have a more complicated structure and are located within the bones that meet behind the eyes.
  • Lastly, the sphenoid sinuses that are even further behind the eyes and behind the ethmoid sinuses. Each of these sinus pockets create mucous and drain it through an opening, called an ostium, to clean both the sinuses and nasal passageways.

Involved Structures and Their Functions

Even though the sinuses are technically only only made up of those four sets of air pockets, there are many other structures that interact with them. One such structure is the nasal septum, which is the part of the nose that separates the two nasal cavities. It is made up of both bone and cartilage and provides structural support for the nose. In healthy cases, this nasal septum will aid the sinuses by allowing air intake and mucous drainage. However, many people experience deviated septum, which means that the nasal septum is misshapen. This can cause a blockage which disrupts the functionality of both the septum and the sinuses.

Turbinates are small bone growths on the walls of the nasal cavities that are covered by mucous membrane. There are superior, middle, and inferior turbinates that all help the mucous membrane to regulate airflow and moisturize the air. Each of these turbinates have a cleft, called a meatus, underneath it. The inferior meatus controls the flow from the nasolacrimal duct, which drains tears. The middle meatus controls the mucous flow from the anterior ethmoid, maxillary, and frontal sinuses. The superior meatus drains mucous from the posterior ethmoid sinuses. Sphenoethmoid recess drains mucous from the sphenoid sinuses.

What Is The Function Of Sinuses Overall?

The nose and sinuses serve a protective function for the respiratory system in that they produce and control the flow of mucous. This mucous may seem annoying or unpleasant, but it is protective against foreign bodies. This is accomplished in part by the cilia, or tiny hair-like structures, that line the nasal cavities. These cilia help control the movement of mucous and move the foreign bodies out of the nasal cavities.

Some of the more general functions of the nose and sinuses are to regulate, warm, and moisturize the air that we intake. This involves the sinuses, mucous membrane, and turbinates removing threats and regulating our body temperature, which directly affects the entire respiratory system.