The ethmoid: sieves, mucous and magnets
What is it? A bone at the front of the skull that forms the roof of the cavity of the nose, separating it from the brain. What’s it got to do with sieves? Parts of this bone are riddled with holes, making it look like a sieve ( ethmoid means sieve-like in Greek). The ancient Romans believed the mucus in our nose had drained through the ethmoid from our brain. And magnets? Homing pigeons have magnetic material in their ethmoid bone, and it’s believed this allows them to navigate by sensing the Earth’s magnetic field. We also have magnetic material in our ethmoid, but its function, if it has one, is unknown. What can happen if it is broken? This delicate bone can fracture after blows to the nose, which can damage nerves that allow us to smell. Ethmoid fractures can also open up a passage between the nose and the eye, causing the eye to bulge out when people sneeze.