what does the frontal sinus do
Frontal sinus. The frontal sinuses are pockets of space located above the orbit of each eye in the frontal bone. They are lined with mucus membrane, which secretes fluid that moistens and protects the areas it covers. The size and shape of the frontal sinus can vary from person to person.These spaces fill up with mucus, which then drain into the nose. The draining process can be hindered by blockages. If mucus accumulates, this can cause infections.hey are lined with mucus membrane, which secretes fluid that moistens and protects the areas it covers. The size and shape of the frontal sinus can vary from person to person. These spaces fill up with mucus, which then drain into the nose.