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.
The planet Neptune takes about 16 hours, 6 minutes, 36 seconds for one complete rotation, as evidenced by its visible outer atmosphere. This is a day on Neptune. That's ab â¦ out 2/3rds of an earth day. Note that the period of rotation is measures by watching Neptune's magnetic field.