Why does a headshot usually mean immediate “turn off” for the brain?
In: 137
When something like a bullet passes through your brain, it creates a cavitation effect that warps and bends the surrounding matter. This has an effect like getting punched really hard, but directly on the brain, which can instantly knock you out
If it’s a “through and through” shot, your brain doesn’t “immediately” shut down, but it effectively may as well be. We can’t say for certain what processes occur exactly, but it’s something along the lines of the brain freaking out and “short circuiting” because of the missing brain tissue, causing something akin to a massive seizure, which then leads to death. This all happens in the matter of milliseconds, but you’re not consciously aware of it due to the “being knocked out” thing.
With the brain being a pretty mushy organ effectively floating in liquid to begin with, a bullet passing through at high velocity will impart a lot of force on all that viscous material, displacing things and causing all sorts of chain reactions with devastating effects.
Just imagine this happening inside the skull: https://www.youtube.com/watch?v=hlXg_H5Jr4g
Are you talking about being literally shot by a bullet, or is this more about being struck by a blow (say, from a punch or a kick)? Others have explained the bullet scenario, but I’m not sure that’s necessarily what you meant to ask, so here’s the blow scenario.
The head has a number of mechanisms, from the soft layers of meninges to the cerebrospinal fluid, that serve to cushion most knocks. But there are limits to how well this can work. A sudden, sufficiemtly powerful blow can still cause the brain to plow into the skull wall at high speed: in other words, a concussion. We tend to think of this happening in high-impact sports like lacrosse and American football, but in the right circumstances a kick or even a punch can also work. That’s why sporting headgear is important.
People do survive gunshots to the head. It is more likely to die but not certain.
Those shot in the head don’t actually have an immediate lights out moment, at least not always. That is a Hollywood trope.
In reality, bullets do massive amounts of damage and modern bullets are specifically designed to destroy soft squishy bits. The reason they are built this way is to make them more lethal and to make it less likely they go out the back of your target and hit someone else.
Since they do maybe damage to the brain, and the brain is where your thinking happens, it becomes very difficult to carry on thinking normally after being shot.
One thing that prevents brain damage is the fact that the skull is very hard and thick. A shot to the head can easily hit the skull and be deflected so that it only damages the skin and not the brain itself.
Either low calibres ping pong around in the skull and turn your brain to soup, or high calibres carry your brain out the back with them.
You can survive. There’s been lots of cases of people surviving with arrows in the head. Not for very long, but still surviving. There’s also the famous case of the man who get a railroad spike through his head and lived on.