GENERAL HISTOLOGY

Detailed explanation-1: -Melatonin is the only known hormone synthesized by the pineal gland and is released in response to darkness hence the name, “hormone of darkness” [10]. Melatonin provides a circadian and seasonal signal to the organisms in vertebrates.

Detailed explanation-2: -Melatonin is a hormone that’s mainly produced by your pineal gland. The importance of pineal melatonin in humans is not clear, but many researchers believe it may help to synchronize circadian rhythms in different parts of your body.

Detailed explanation-3: -In vertebrate animals, including humans, the master clock is a group of about 20, 000 nerve cells (neurons) that form a structure called the suprachiasmatic nucleus, or SCN. The SCN is in a part of the brain called the hypothalamus and receives direct input from the eyes.

Detailed explanation-4: -The main function of the pineal gland is to receive information about the state of the light-dark cycle from the environment and convey this information by the production and secretion of the hormone melatonin.

Detailed explanation-5: -Pineal melatonin is a hormone that regulates the body’s daily (circadian) clock and so melatonin is commonly used in human research to understand the body’s biological time. There is a rhythm to the biology of the pineal gland and melatonin is secreted according to the amount of day light a person is exposed to.