Is the cranium completely sealed?

July 31, 2007 1:08 PM

Is the brain completely surrounded by bone? Is the cranium a completely contained unit that opens only into the spinal column?

Is there any place on the human head where you can access the brain without piercing bone?

I've been reading about trepanation lately. Too much about it, really.

posted by Baby_Balrog to health & fitness (12 comments total)

Can't you reach it from your nose and/or behind your eyes? Isn't that how lobotomies work?
posted by tastybrains at 1:11 PM on July 31, 2007

The optic nerves behind your eyes run directly to your brain, as do the olfactory ("smell") nerves in your sinuses.
posted by Blazecock Pileon at 1:13 PM on July 31, 2007

You can get in through the eyes and nose. But don't!
posted by tiny crocodile at 1:15 PM on July 31, 2007 [1 favorite]

The Egyptians, during the mummification process, would scramble the brains of the deceased and remove them, all through the nostrils.
posted by Green With You at 1:20 PM on July 31, 2007

Ear. as well. I had thought the palate was another way in, but this site says no. It looks like there are some little openings here and there.
posted by jquinby at 1:21 PM on July 31, 2007

And the ears. Don't forget about those.

And I think if you go in arthroscopically, you can get into the brain by going in from just behind the point of the jaw, near the TM joint. I've seen a video of samples being taken from some sort of cranial tissue that way.
posted by Kadin2048 at 1:25 PM on July 31, 2007

The skull has lots of small openings called foramina which allow blood vessels, nerves, and the spinal cord to go in and out. Wikipedia has an ok list. Googling "netter skull" brings up decent images, like this one which is blatantly stolen from netter. Similarly "skull gray's".
posted by a robot made out of meat at 1:37 PM on July 31, 2007

Also, properly speaking the retina is a piece of your brain. The nasal nerves that people are talking about go through the cribiform palate, but I don't know if you'd count that.
posted by a robot made out of meat at 1:39 PM on July 31, 2007

If you read about trepanation surely you would know that they went in with the ice pick behind the eyes?
posted by fire&wings at 1:50 PM on July 31, 2007

Thanks everyone! These are all good answers. Looks like the hole people get when they're trepanned is nothing special.

i mean, it's certainly special, but not biologically speaking.
posted by Baby_Balrog at 1:57 PM on July 31, 2007

I came here to say that LOBOTOMIES, not trepanations fire&wings, can be done between the eye and the eye orbit.

And seeing Baby_Balrog's last comments, I have this to add: If the trepanation hole is not different from the natural holes, why are trepanations still done to relive intracranial pressure?

I don't have the answer, but at least two people in my family have had pieces of skull removed to save their lives, one because of meningitis, the other after a motorcycle crash.

Proponents of recreational or spiritual trepanation claim hole makes them better persons. It must relieve some pressure, I have no idea if this improves anyones lives, both my relatives had the holes covered with metal plaques as soon as they were out of danger.
posted by Dataphage at 2:54 PM on July 31, 2007

... why are trepanations still done to relive intracranial pressure?

Because the naturally-occuring foramina in the skull are filled with tissue like nerves and blood vessels and can't be used to regulate intercranial pressure.
posted by jesourie at 4:42 PM on July 31, 2007