happy hunger games

Are you going to see the Hunger Games today? I am. I imagine since it’s opening day, it’s going to be packed. But that’s okay… if Katniss can brave a trackerjacker attack, I can brave a bunch of 12-18 year olds. I think.

In honor of the Hunger Games, we’re going to explore the fight or flight response. I’m sure you’ve heard of it and know a bit about it. On the surface, it’s basically a behavioral response that has evolved to increase our odds of survival when faced with peril. But let’s get a little grittier and talk physiology.

All your bodily processes are dependent on your nervous system. It is divided into two main systems- somatic and autonomic. You can infer their function from their names. Somatic, meaning “bodily,” is the network of nerves you control. Walking, turning your head, writing, scratching your head, whatever. It is fed information primarily from the hemispheres of the brain. Autonomic nervous system is in charge of all the processes you would consider “automatic” or involuntary like respiration, digestion, blinking, your heart beating, hormonal regulation, sweating, and getting frisky. It is controlled by your brain stem, meaning it is of rudimentary evolutionary origins.

So, since it’s science, we have to divide these systems further because two categories just aren’t enough. Your autonomic nervous system is divided into two more systems- parasympathetic and sympathetic. The parasympathetic is in charge of maintaining your body at rest, which is pretty much digestion and hormones. But your sympathetic…. that’s what you want around in a trackerjacker attack. It activates during a time of stress and tells your muscles what to do when you may not have enough time to sit and think about it. Cato will surely have speared you by the time you consciously figure out the best way to handle him.

The sympathetic system is what is in charge of the flight or fight response. At the moment you realize you’re in trouble, your sympathetic system douses your tissues with the hormone adrenaline, which allows for extremely quick and sudden muscular activity. It also increases your heart rate, breathing, pupil size, and blood vessel constriction.

I think what it inhibits is even more interesting. It temporarily shuts down digestion, tear and spit production, some hearing ability, an erection (if you are a male and have one…. awkward), and peripheral vision. While some of these reactions may surprise you, you can figure out that they function to eliminate extraneous and unessential processes so that maximal energy can be devoted to vital ones- the ones that will help you come out of the situation alive. You don’t need to be digesting that Whataburger you had for lunch at a time like this, and your sympathetic nervous system knows it.

When this response is combined with sensory input, it allows for your brain to make a rapid assessment on what to do. In some cases, you’ll run. In other’s you’ll fight back. It depends on lots of environmental and situational variables, but your sympathetic nervous system has primed and prepped your body for action one way or the other.

I know you’ve experienced this stress response before… probably in a near miss while driving. It takes a few minutes to process the adrenaline out of your bloodstream and calm down. Thousands of years ago, however, this response was more likely elicited by Thor from the tribe on the other side of the river coming after you with a club, or a bear the size of a Buick trying to eat you. I find it funny that nowadays, this very same response can be initiated by realizing you forgot to pay rent.

But this is not so in future Panem. They’re not worried about paying rent or getting in a fender bender, they’re worried about other adolescents beating their heads in with a log in the Hunger Games. Katniss and Peeta better hope they have fully functional sympathetic nervous systems, or else they’ll be like fish in a barrel.

Happy Hunger Games, and may the odds be ever in your favor!