a catecholamine secreted by the adrenal medulla in response to stress (trade name Adrenalin); stimulates autonomic nerve action
"The sudden jump scare at the haunted house triggered a massive release of adrenaline, making my heart race and my hands shake uncontrollably."
epinephrine, the hormone and neurotransmitter.
"The doctor explained that his heart rate spiked because a surge of adrenaline flooded his bloodstream after the accident."