12/02/2025
Great read on the 2 operating systems of your brain/body.
Your body is running TWO operating systems at the same time… and you never notice.
One keeps you alive when you’re calm.
The other keeps you alive when you’re in danger.
And they’re constantly switching control behind the scenes, every second of your life.
This chart reveals the entire autonomic nervous system on one page:
• The parasympathetic system (rest, digest, recover)
• The sympathetic system (fight, flight, focus)
If you’ve ever wondered why stress wrecks digestion, why panic spikes your heart rate, why your mouth dries up, or why deep breathing instantly calms you, it’s because these two systems are battling for control of the same organs.
Here are a few details hidden in the diagram:
🔹 One nerve (the vagus) influences your heart, lungs, gut, liver, pancreas, and more.
🔹 Your pupils dilate and your stomach shuts down the moment your brain senses threat.
🔹 Stress reroutes blood from digestion to your muscles in seconds.
🔹 Your body can literally flip between “build/repair” mode and “survive now” mode automatically.
Most people never see how all these pathways connect, but once you do, the effects of stress, sleep, anxiety, posture, breathwork, and exercise make a lot more sense.
If you want a single picture that explains why your mind and body feel dramatically different under stress vs. calm… this is it.
Source:
Color Atlas of Pathophysiology, Thieme Publishing.