Jetlag Explained, Quickly

Jetlag makes us tired, but unable to sleep. It makes us disoriented, even though we know exactly where we are. It makes us irritable about things that should not irritate us. How does it work? The answer, apparently, has something to do with the suprachiasmatic nucleus–but you knew that.  The suprachiasmatic nucleus, of SCN, is located in the hypothalamus, and is filled with neurons, all with synchronized circadian rhythms that help us regulate sleep and wakefulness. As this story in the Los Angeles Times reports, SCN comprises two sections, dorsal and ventral, and each section tracks changes in light and darkness, which is then coordinated with our sense of time. To make a long and complicated story very short, but link to the complicated story, when the we fly, the two parts of the SCN can fall out of sync with each other, as well as out of synch with other "peripheral clocks" throughout our bodies. When that happens, our bodies sense of time, and in some cases, well-being, begins to give way to confusion and irritibility. We call it jetlag, for obvious reasons: it’s much easier to pronounce than suprachiasmatic nucleus.