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Human Body Study

Pineal Gland

A tiny gland deep in the brain.

The endocrine system A stylised body with the eight endocrine glands placed at their anatomical positions: hypothalamus, pituitary, pineal, thyroid, parathyroids, adrenals, pancreatic islets and gonads. Each label links to the article for that gland. Hypothalamus Pituitary gland Pineal gland Thyroid gland Parathyroid glands Adrenal glands Pancreatic islets Gonads The endocrine glands at their anatomical positions — schematic, not to scale.

What it produces

Section titled “What it produces”

Melatonin — the hormone of the daily sleep–wake rhythm.

What it does

Section titled “What it does”
  • Releases melatonin in darkness and suppresses it in light, tuned by signals from the eyes.
  • Sets the body’s circadian rhythm and signals “night” to the rest of the body.

Key idea

Section titled “Key idea”

The pineal gland is the body’s clock hand — it converts the light–dark cycle into a hormonal night-time signal.