|67 : zeitgeber
||[Sep. 5th, 2004|06:07 pm]
Word Of The Day
zeitgeber (n) \TSYTE-gay-ber\|
: an environmental agent or event (as the occurrence of light or dark) that provides the stimulus setting or resetting a biological clock of an organism
Light is known to be a zeitgeber that helps to keep both plants and animals on their normal daily and seasonal schedules.
Zeitgebers are nature's alarm clocks — both biologically and etymologically. The word "zeitgeber" derives from a combination of two German terms, "Zeit," which means "time," and "Geber," which means "giver," so a "zeitgeber" is literally a "time giver." In nature, zeitgebers tend to be cyclic or reoccurring patterns that help keep the body's circadian rhythms operating in an orderly way. For plants and animals, the daily pattern of light and darkness and the warmer and colder temperatures between day and night serve as zeitgebers, cues that keep organisms functioning on a regular schedule. For humans, societally imposed cycles, such as the schedule of the work or school day and regular mealtimes, can become zeitgebers as well.