Words to Expand Your Sleep Vocabulary

From the German for “time giver,” zeitgeber refers to any external cue that can entrain (or reset) the time-keeping system of organisms. In humans, this circadian system, or biological clock, is located in the suprachiasmatic nucleus within the hypothalamus of the brain. This system is affected by zeitgebers. These cues follow a periodic pattern. The strongest zeitgeber is the natural pattern of light and darkness.