Function of the Sinuses
Dr. Agustin Arrieta, Otolaryngologist with Baptist Health South Florida, explains there is a theory that explains sinus cavities developed to lighten the load of our head and allow us to walk upright.
He also says there is a second theory that suggests sinuses help produce resonance of our voices. The third one is that sinuses have the function of producing some mucus lining for the nose. He points out sinus infection can spread from one sinus to another, because there is a common drainage area, and if it becomes obstructed then there is a backflow of mucus fluid and infection into the sinuses.
