She is considered to be an expert on sleep and circadian rhythms during childhood and adolescence along with issues related to daytime sleepiness.
en.wikipedia.org Also, within the cranium, the pineal gland, which attaches to the thalamus, controls the body's 24 hour rhythms circadian rhythm through the release of melatonin.
en.wikipedia.org One particular component, the suprachiasmatic nuclei, is responsible for the circadian (or daily) rhythm, while other cell clusters appear capable of shorter-range (ultradian) timekeeping.
en.wikipedia.org Sightless cells hidden within the eye may set our circadian rhythms, trigger migraines, and explain the seasonal ebb and flow of our moods.
discovermagazine.com In addition to circadian misalignment, attempted sleep at unusual times can be interrupted by noise, social obligations, and other factors.
en.wikipedia.org