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.
Neptune orbits around the sun every 165 years at an average distance of 2.8 billion miles (4.5 billion km). It spins on its own axis every 16 hours compared to 24 hours on Earth. Due to its far distance from the sun Neptune has an extremely cold outer atmosphere with temperatures averaging around -220C (-364F).Temperatures at its center rise to around 5000C (9000F). Neptune has 13 known satellites, the largest being Triton (picture right) which has a diameter of around 1,681 miles (2,705 km).ue to its far distance from the sun Neptune has an extremely cold outer atmosphere with temperatures averaging around -220C (-364F). Temperatures at its center rise to around 5000C (9000F).