Adrenaline is a hormone and neurotransmitter produced by the adrenal glands in response to stress or danger. It is responsible for the "fight or flight" response in the body, which prepares you to react quickly to a threat. This response increases heart rate, blood pressure, and energy supply, enhancing your ability to perform physically in a challenging situation.
The term "adrenaline" comes from the word "adrenal," which refers to the adrenal glands located above the kidneys. The suffix "-ine" is often used in chemistry to denote substances. The word was first coined in the late 19th century.