Which gland is responsible for secreting melatonin?

The pineal gland is responsible for secreting melatonin, which is a hormone that regulates sleep-wake cycles. Located in the brain, this small, pea-shaped gland plays a crucial role in the body's circadian rhythms. The production of melatonin is influenced by light; it is secreted in higher amounts during the night and lower amounts during the day, helping to maintain sleep patterns.

This gland's function is vital for signaling to the body when it is time to sleep, which is closely linked to the exposure to natural light. Thus, understanding the role of the pineal gland in melatonin secretion is key to grasping how hormonal regulation affects sleep and various biological processes related to daily cycles.