Jupiterimages/Brand X Pictures/Getty Images. Panic is a natural reaction when you're served with a subpoena, but as far as legal documents are concerned, a subpoena duces tecum is one of the more innocuous ones you can encounter.
Circadian rhythms are biological oscillations that recur with a period of approximately one day. Health issues related to circadian rhythms include jet lag, shift work, seasonal depression, and time-of-day variations in response to medical treatments.
The pineal gland is a neuroendocrine organ located in the midline of the brain. Melatonin, thought to be the output hormone of the pineal gland, plays a central role in the co-ordination of circadian rhythms and the circadian system. Circadian rhythms are centrally co-ordinated and physiological, psychological and behavioural processes, which in humans follow approximately a 24- to 25-hour alternating cycle. In humans, circadian rhythms are genetically programmed to synchronise with night and day.