In literary usage, a scion is usually the young member of a rich, famous or distinguished family. Another sense of the word scion describes a shoot of a plant, especially one taken from another for replanting. A branch or portion of a tree growing from such a shoot is called a graft. Scientists long ago ruled out airline food and forced exposure to hours of droning conversation from the bore in the seat next to you as causes. The funny thing is that the cause most people would point to, a change in time zones with the accompanying confusion with meal and bed times is also apparently not the only answer.
Many people flying North to South, without changing time zones, also suffer from jet lag.
Most likely it's the pressurized cabin with its low humidity, the plane's vibration, engine noise, and radiation from the high altitude. In other words, your body is being assaulted while you sit there with your seat belt fastened. Drink plenty of water, move around the cabin, and take vitamin supplements. The popular Scotch tune was written by Robert Burns and was first published in 1796. The first television show to show a flushing toilet was Leave It to Beaver.