The body's internal master clock
What happens when the clock breaks
The mystery of the eastbound flight
The hidden costs of chronic jet lag
Outsmarting the lag
What external cue is the primary synchronizer, or 'zeitgeber,' for the human master clock?
Which organ contains 'peripheral clocks' that can get out of sync with the brain during jet lag?
diego Play the Body Clock Buddy game to learn how jet lag impacts your internal master clock and affects your circadian rhythm.
Which hormone, produced by the pineal gland, rises in the evening to signal it is time to sleep?
Approximately how many neurons make up the human master circadian clock in the hypothalamus?
diego Circadian Rhythm
Your body's rhythm, a twenty-four hour tide! (Oh-oh!) Needs a day per time zone, to switch its stride! (Yeah-yeah!)
Why did early single-celled organisms first evolve circadian rhythms billions of years ago?
Master clock size: The suprachiasmatic nucleus is only about the size of a grain of rice but controls your entire body's daily schedule.
What happens to human core body temperature during the night as part of the circadian cycle?
A pair of small nerve cell clusters in the hypothalamus that regulates circadian rhythms. It contains approximately 20,000 neurons that coordinate biological rhythms with the environmental light-dark cycle.