AP PSYCHOLOGY

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: -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-3: -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.

Detailed explanation-4: -The production and release of melatonin from the pineal gland occurs with a clear daily (circadian) rhythm, with peak levels occurring at night. Once produced, it is secreted into the blood stream and cerebrospinal fluid (the fluid around the brain & spinal cord) and conveys signals to distant organs.