Warning: This is another graphic dissection-related post and possibly contains some of the grossest descriptions yet. I also might ruin oranges, cottage cheese and s’mores for you forever. Read at your own risk.

Do you know what you get when you send out an email asking medical students if they would like to give up an afternoon to assist with an optional brain removal dissection? A lab full of medical students wielding bone saws and chisels.

Where do we cut? The top part, right?

(If you’re already rethinking your commitment to reading this post, the back button should be at the upper lefthand corner of your screen.)

We’ve started our unit on the central nervous system, which means I am in full neuro-nerd mode. (Another student called me that earlier today and I like the alliteration so well I decided to keep it.) We’re not actually doing a lot of cutting in our dissections for this unit, but the brains did need to be retrieved from their usual location. The idea was to use all of the brains from our cadavers along with a few supplemental brains* from surgical pathology so that we won’t have to alternate dissection groups like we have been doing with our cadavers.

Here is how to remove a brain:

First you have to remove the skin of the cranium. You do this by making an incision from between the eyes to the back of the head and from one ear to the other and then peeling back the flaps. This was a bit more intimate than I was expecting, given that we had covered the face of our cadaver on the first day of lab and had not uncovered it since. The rest of his body was devoid of skin except for the soles of his feet and the backs of his hands. In many ways our cadaver had ceased to feel like something that had once been a person. Uncovering his face and making that first incision between his eyes was different. I have a hard time attaching an emotion to it–I didn’t find it sad or gross or creepy–but I noticed it.

Peeling the skin off the bone of the scalp is like peeling an orange. It comes away with a good solid tug and makes that same soft unsticking sound The deep fascia underneath even looks like the white inner rind. Underneath, the top of the skull looks just like every skull you’ve ever seen, off-white and smooth. The temporalis muscle on each side (the thing that tightens up at your temple when you clench your teeth) is the only non-boney landmark. We reflected them back as well so that we would only be sawing through bone.

The striker saws have small, semi-circular blades. They cut through the bone pretty easily, but they are just unwieldy enough that it’s hard to judge how deep you’re going. The goal is not to saw through the entire bone, but rather a few millimeters deep and then to crack the rest of the way through with a chisel and hammer. Halfway through this process you have to flip your cadaver over to make a complete circle around the head. Then you flip it onto its back and saw across the top like a headband.

The bone saws kick up a lot of bone dust and the friction creates a bit of smoke. It smelled to me like burning marshmallows. (No, I wasn’t hungry during this dissection, I swear! I reasoned it out with another student later: marshmallows and bones are both made of gelatin, after all.)

Some of the cadaver brains weren’t properly embalmed, which brought a whole new meaning to the phrase “my brain is mush.” They were the consistency of cottage cheese and oozed out of the new opening in the skull. Even the anatomy professor was grossed out. Those brains were left in their respective cadavers with several layers of wrapping around them both.

Our brain was well-preserved. The skull cap made a ripping/popping noise as it came free: the sound of the dura mater (the tough, protective coating of the brain) pulling free of the bone. Then we sawed through the occipital bone at the back of the head so that the spinal cord could be severed.

Even then, there was a lot more to be disconnected: the roots of the dura mater, the vessels that carry blood into the brain, all of the cranial nerves (there are twelve pairs.) Then we were done, and the brain came free like it was never all that attached in the first place. What, all that work just for me?

Strange to think that the object I was cradling carefully in two hands (not-dropping a brain on the first day was pretty high on my to-do list) had held all of the thoughts, the memories, most of the personality of the person it once belonged to. It is dead now, fixed and quiet, but I wonder if someday we might be able to look at all of the connections that existed and see something of the thoughts that passed through it once. Or maybe we’ll discover that to be something completely unknowable, something greater than the sum of its parts. It sort of hurts my own brain to contemplate. In a good way.

Ze Brain

*Every time I say the phrase “supplemental brain” I want to make a joke about borrowing one for the next exam. I know, it’s terrible, but I just can’t resist.

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