GENERAL HISTOLOGY

Detailed explanation-1: -Melatonin is a natural hormone that’s mainly produced by your pineal gland in your brain. It plays a role in managing your sleep-wake cycle and circadian rhythm.

Detailed explanation-2: -Melatonin is an important hormone in circadian synchronization. This hormone is involved in many biological and physiological regulations in the body. It is an effective hormone for human biorhythm (circadian rhythm).

Detailed explanation-3: -Melatonin is produced from serotonin (made from tryptophan), through a cascade of enzymatic reactions (Figure 1).

Detailed explanation-4: -Darkness prompts the pineal gland to start producing melatonin while light causes that production to stop. As a result, melatonin helps regulate the circadian rhythm and synchronize the sleep-wake cycle with night and day.

Detailed explanation-5: -In humans and most diurnal mammals, melatonin is secreted at night with a robust circadian rhythm and maximum plasma levels that occur around 3 to 4 AM. The daily rise of melatonin secretion correlates with a subsequent increase in sleep propensity about 2 hours before the person’s regular bedtime.