I’ve heard that a human brain has the physical consistency of… (thinking)… Jelly?.. no jelly’s too soft… ok so I can’t remember the acutal substance, but the point is the brain is soft and squishy.
I often wonder this. Quite surprised I’ve never asked it here before. How does it not get damaged by the things that happen to our head? I know the skull is a very hard thing but wouldn’t the sudden movements cause rips of some other damage to the brain?
People often bang their heads quite severely and the worst they get is pain in the nervous system of the skin. The brain survives intact.
People also sometimes ‘vibrate’ their heads to ‘clear’ their perception. (you know what I mean. you feel unsure about what you are seeing so you shake your head)
When I do this myself I imagine the brain being squishled about like a yolk in a shaken egg.
My personal approach is to not spend too much time in Great Debates.
But from a physical point of view, the brain is cushioned by fluid, and, to a certain degree, by resilent tissue (the dura, I think). Sort of like a shock absorber – any impact is spread out over a few miliseconds, reducing the impact. But the real answer is, it doesn’t take all that much to cause damage. That’s why you get concussions if you bang your head badly enough or someone wallops you in the right place. And unlike all the TV movies, a concussion isn’t something you just walk off.
Not to hijack the thread or anything, but do people actually do this? I’ve never done it, nor have I ever seen anyone else do it (outside of old Bugs Bunny cartoons). I just always assumed it was an invented cartoon convention.
In the case of severe whiplash, something bad that does happen sometimes is that the brain is thrown into the front of the skull–but cushioned and comes out in tact–but the pituitary gland, which is held in a little cage of bone, is detached from the rest of the brain. The person then has lots of hormonal deficiency problems.
That is a good comparison. I have handled many, many human brains and as long as you hold them in the palm of your hand, they don’t deform at all. However, if you take your fingers and squeeze on any part of it, it crushes and turns into mush. It is amazing how the most powerful computer known could be destroyed by a preschooler sticking a finger through it like it is Play Dough.
Practical exercise. I knew a kid in the Air Force who had some spinal fluid drained for some test or other. Doc told him to go home and lie still for the rest of the day because his fluid pressure was low. He didn’t. He came to class anyway and spent a few minutes leaning his head forward…raising back up…leaning forward…
“Aidle, what are you doing?”
“when I lean forward I can feel my brain hitting the front of my skull…it’s weird.”
He went back to his room shortly after that. For a few days.
I’ve found myself doing it as a quick way to snap back into concentration while under the influence. If I need to pay attention to something while very drunk, it’s much better than just waiting for the fog to clear.
If this happens at all, its extremely rare. What you may be thinking of is the brain being injured by scraping over the uneven surface of the base of the skull. This happens with basilar skull fractures.
The injury is actually to the uncus which contains the reticular activating center. In lay terms, its your alarm clock. Its the part of the brain that that makes you awake.
If its injured, you are unconscious. When injured it swells, and being part of the brainstem, can be forced into the large opening in the skull where the spinal cord lies (Foraman Magnum). This causes CSF to collect in the skull, causing increased intercrainal pressure, which causes damage to the other soft structures, which includes the pituitary and optic nerves. The patient’s pupils become dilated and nonreactive, the kidneys aren’t able to concentrate urine. As the brainstem is pushed further into the Foraman Magnum, the autonomic functions, like breathing and heart beat cease. The result is death.
When the head is hit hard, the brain moves away from the injury, only to be slammed into the other side of the skull. This is called a contrecoup injury. It can cause a slight concussion, with a headache and nausea, to sudden death, and everything in between.
To demonstrate, fill a small tupperware style bowl with water and put the lid on. Put that bowl in a bigger tupper, fill that one with water, and put on the lid. Hit the side of the big bowl hard enough to move it a foot or so. watch what happens to the little bowl. This won’t be a perfect demo, but if you want a more acurate one and are willing to do some work… Make somewhat concentrated jello in the small bowl, put just the jello in the larger bowl do the experiment immediately, as the jello will melt in the water.