home / medterms medical dictionary a-z list / ethmoid sinus definition Medical Definition of Ethmoid sinus Ethmoid sinus: A collection of air cells within the ethmoid bone, a spongy bone which makes up the front of the floor of the skull and the roof of the nose. From the Greek ethmos, sieve + eidos, resemblance = like a sieve.
Confidence votes 84.8K. It takes 4.05 hours to 4.12 hours for light from the sun to reach Neptune, depending where it is in it's orbit. It takes 4.05 hours to 4.12 hours for light from the sun to reach Neptune, depending where it is in it's orbit.
Upper atmosphere. Neptune, the eight and last planet in the Solar System is named after the Roman god of the sea. This green-bluish giant is quite similar to Uranus in size and composition, but is much farther from the Sun. It takes about 164 years to orbit the Sun. Like other gaseous planets Neptune turns fast on its axis, making the day only about 16 hours long. Though you can't see Neptune with the naked eye.