The Pineal Gland

The pineal gland is found on the dorsal (upper) side of the forebrain. It secretes a single hormone called melatonin.

Melatonin and the body's daily rhythm

Melatonin's most important task is to help regulate the body's 24-hour (diurnal) rhythm — the internal daily cycle that keeps body processes timed to the day. Through this role it helps maintain:

• the normal sleep–wake cycle
• normal body temperature

Its wider effects

Beyond timekeeping, melatonin also has an influence on several other functions of the body: …