Gland

A gland is a group of cells in the body which make substances such as hormones. They are in humans and other animals, and in plants.

• If the substance is put directly into the bloodstream, the gland is called endocrine gland.
• If the substance is carried by a duct, the gland is called an exocrine gland. Exocrine ducts empty outside the body, or into cavities inside the body.

Examples of glands in humans are:

• Sweat glands that produce sweat for perspiration.
• The pineal gland in the brain, which produces the hormone melatonin at night.

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