Something wonderful happens, when our bodies are stressed beyond our means. The human system — ever expert at staying alive despite all odds — responds to threats with a biochemical cascade of various hormones (including adrenaline/epinephrine and noradrenaline/norepinephrine) which not only reduce sensitivity to pain, but also sharpen a select group of coping mechanisms to keep you from being injured (or eaten).
Note: In case you’re wondering about this, the words adrenaline and epinephrine, and noradrenaline and norepinephrine are often used interchangeably. Epinephrine and norepinephrine are the official names for the hormones our adrenals produce, but we tend to call them adrenaline and noradrenaline, as well.
The process essentially works like this:
- Something happens that isn’t “normal” or expected, like a sudden loud sound or flashing lights.
- The senses relay the perception of this environmental “stressor” from the sensory cortex of the brain through the hypothalamus to the brain stem. In the process, “noradrenergic” activity (which is connected with norepinephrine/noradrenaline) picks up in the brain, and you become instantly alert and attentive to what’s going on around you.
- A sudden rush of stress hormones at neuroreceptor sites in your brain tells your whole system to use its spontaneous or instinctive/intuitive behaviors which keep you alive in combat or escape situations. Your brain takes non-essential functions “offline” and pours its energy into only the most vital elements of survival.
- Your body is infused with energy, your mind is suddenly clear and wiped clean of extraneous distractions that have nothing to do with saving your ass, and you’re immediately ready for action.
The process is purely automatic, and the brain knows quite well how to kick into survival mode. If it didn’t, you – and everyone else – would probably be dead, and the planet would be inhabited by creatures that did know how to survive by brute force and instinct. Possibly ticks.
Now, things get really interesting, if you perceive a stimulus as a threat. The “firing” in your brain becomes more intense and prolonged, and the sympathetic part of the autonomic nervous system (the part that responds to threats and stressors) gets all worked up. (Remember, the other part, the parasympathetic nervous system, is what calms us down and chills us out.) In the process of sympathetic nervous system arousal, a bunch of epinephrine (adrenaline) and a bit of norepinephrine shoots into your system from the little star-shaped adrenal glands, which sit atop the kidneys (the word adrenal comes from ad (atop) – renal (kidney), or literally on top of the kidneys) and regulate the release of the stress hormones adrenaline (epinephrine), noradrenaline (norepinephrine), as well as cortisol into our sensitive systems.
The release is, again, totally automatic, totally necessary, and pretty much beyond our control. It’s also triggered by other biochemicals that originate within our intricately wired brains, which I cannot pronounce and have a hard time spelling. There are other complex factors that come into play, but basically, this is how your adrenaline-pumped fight/flight response gets started in your brain.
But wait – there’s more. The rest of your body is drawn into the action, in the following ways. The list below is not exhaustive, but it gives you an idea of what goes on:
- Your heart beats faster and you start to breathe faster/pant/hyperventilate
- You pale or flush, or you alternate between both
- Your stomach and upper-intestinal action go off-line, and your digestion slows down or stops altogether
- Lots of blood vessels in many parts of your body constrict
- A “shot” of glucose – sugar, sugar, sugar – gets released into your body to fuel muscular action
- Blood vessels in your muscles open wide to allow more blood to pass through (there’s more blood available to them, since vessels in other parts of the body constrict)
- Your eyes and mouth can get dry
- Your pupils dilate, so you can see better
- Your bladder may relax and your colon may empty (hence the popular expressions “pissing or shitting your pants”)
- Erection is inhibited (the body needs the blood elsewhere, including for your muscles – see above)
- You can lose (some or all of) your hearing for a while
- You can lose your peripheral vision for a while
- Instantaneous reflexes accelerate and become hyper-responsive.
All this basically spring-loads you for action, and it’s wholly automatic. You couldn’t stop the neural/biochemical escalation in a crisis, if you tried. (Well, some people probably could, but they’ve very likely been sitting in intensive zen meditation for years or they’ve received training in how to do this, which most of us have not.) Signals get fired in the brain, screaming Run!!! Run!!! or Fight!!! Fight!!! overriding (by design) your rational brain that wants to sit back and assess the situation and not get all worked up until there appears to be a good reason.
And it totally saves your ass. Like an instinctive response to the shrieking wail of approaching fire truck sirens, bright red lights suddenly flashing through your bedroom window at 3 a.m., and/or the smell of a big smoky fire coming from the apartment next door. Your body takes over automatically, making you instantly alert and highly attentive to what’s going on around you. As your brain takes non-essential functions “offline”, everything around you fades to a blur, except for the sound of roaring flames tearing through the building, the scent of thick smoke, and the sight of the window across the room that leads to the fire escape. Suddenly, the petty distractions of the day before mean absolutely nothing, as do any extraneous activities not related to living to see another day. Forget about making the bed and fluffing the pillows and making sure your hair is combed before you go outside – pull on your bathrobe, grab your keys and the cat, and climb out the bedroom window onto the fire escape. Don’t worry if the firemen can see up your shorts – just get the hell down to the ground level and away from the flame-engulfed building.
When it comes to basic survival, we’re hard-wired to make sure we get through in one way or another, and the tidal wave of biochemicals that floods our system really does take over, whether we like it or not. If those handy hormones do their jobs properly, they give us the chance – after we’re once again hauled out of the fire to safety – to sit back and process what just happened and decide in retrospect if we should have gotten worked up or not. But if they don’t do their job and we end up on a cold slab, we never get the chance to sort things out. So, it’s not a bad thing, that our survival brain hijacks the rest of our cognition in situation-appropriate ways.
It’s not a bad thing at all.
A Perilous Relief – Table of Contents
traumatic brain injury, trauma, threat, thoughts, tbi education, tbi, sympathetic nervous system, stress, risk, post-traumatic stress, post traumatic stress disorder, parasympathetic nervous system, mtbi, mental health, life, head injury, fight-or-flight, fear, epinephrine, danger, crisis, coping strategies, cognitive-behavioral issues, central nervous system, brain damage, brain, anxiety, analgesic stress, agitation, adrenaline rush, adrenaline, Personal Experiences with TBI, PTSD, Neuropsychological Effects of TBI, Mild Traumatic Brain Injury, Head Trauma, Brain Injury