pineal gland

noun

1. a small, cone-shaped endocrine organ in the posterior forebrain, secreting melatonin and involved in biorhythms and gonadal development.

pineal gland

noun

1. a pea-sized organ in the brain, situated beneath the posterior part of the corpus callosum, that secretes melatonin into the bloodstream Technical namesepiphysisepiphysis cerebri

pineal gland

1. A small gland located near the brain and primarily involved in the production and secretion of the hormone melatonin, which regulates circadian rhythms in many animals, including humans.

Word History and Origins

Origin of pineal gland¹

First recorded in 1705–15

Example Sentences

Melatonin is produced naturally in the pineal gland to signal the body that it is time to sleep and regulate its circadian rhythm -- the physiological cycle over a 24-hour period.

From Science Daily

These supplements, including sugary gummies, typically offer much higher doses than what the pineal gland produces to help shift circadian rhythm to night mode.

From Scientific American

Melatonin is a naturally occurring hormone produced by the pineal gland, a small structure at the center of the brain.

From Washington Post

It inhibits the production of natural signals such as melatonin, a hormone that is produced by the brain's pineal gland as the night arrives and in response to darkness.

From Salon

Melatonin is a naturally occurring hormone produced by the pineal gland that helps regulate the sleep-wake system.

From Washington Post