Long before cities, technology, or even humans existed, animals needed a way to rapidly prepare their bodies for sudden changes around them. Adrenaline became an important part of that evolutionary mechanism. Within moments, it can change the way the heart works, redirect blood flow, widen the airways, mobilize stored energy, and temporarily shift the body’s priorities. All to make more resources available exactly when they are needed. And that strange “sour” or hollow feeling you sometimes notice in your chest when you’re suddenly frightened or extremely nervous? Adrenaline and the wider stress response are a big part of that sensation. Your cardiovascular system, breathing, muscles, and nervous system are all changing their activity almost simultaneously. Adrenaline is both a hormone and a neurotransmitter-related chemical messenger. It is produced mainly by the adrenal medulla and acts on adrenergic receptors throughout the body, especially α and β receptors. Different tissues respond differently, which is why one small molecule can produce so many effects at once. We usually associate adrenaline with fear or excitement, but it isn’t something “bad” that the body produces. It is an essential regulatory mechanism - one that helped our distant ancestors adapt to rapidly changing situations and still quietly works inside us today. A tiny molecule with an enormous effect on the entire body. #Adrenaline #Biology #HumanBody #edit #medicine - @pitochk