se7enW
Back to What
📖 what

What Is a Hormone?

BiologyHealth

Quick Answer

A hormone is a chemical messenger produced by endocrine glands that travels through the blood to regulate distant organs and body processes.

The Full Story

Hormones are signalling molecules secreted by endocrine glands (such as the pituitary, thyroid, adrenals, and pancreas) directly into the bloodstream. Even in tiny concentrations (parts per billion), they regulate a vast array of body functions: growth (growth hormone), metabolism (thyroid hormones), blood sugar (insulin and glucagon), stress response (cortisol and adrenaline), reproduction (oestrogen, testosterone), sleep (melatonin), and mood (serotonin and dopamine act as both neurotransmitters and hormones). Hormonal imbalances can cause conditions ranging from diabetes to thyroid disorders to infertility.

Key Facts

1.The word "hormone" comes from the Greek "hormon," meaning "to set in motion."
2.Insulin, discovered in 1921, was one of the first hormones identified and remains essential for treating diabetes.
3.The hypothalamus, a brain structure the size of an almond, is the master regulator that controls the endocrine system.

YouTube Angle

Suggested video title for this topic:

"Hormones — The Chemical Messengers Running Your Body"