Archive for the ‘Peripheral Nervous System (PNS)’ Category

Dreams and Spinal Taps

August 28, 2007

When Dr. Greenwald said yesterday in class “trust me, tonight, you’re gonna dream about this [expletive],” I didn’t really take him seriously. That is, until last night when I did indeed dream about the brain. I tossed and turned all night, dreaming about the brain and that somehow I was getting it wrong and that I didn’t want to fill my thoughts with wrong material so I was getting more and more worried which cause me to sleep worse and worse.

Also, I forgot to mention in my previous post: when we got to the part about Lumbar Punctures, aka: a spinal tap, Dr. Greenwald had us watch a clip on YouTube from the mockumentary about the fake 80’s hair band Spinal Tap. It was hilarious. I love this professor.

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Gross Anatomy, The Ventricles, and The Meninges

August 27, 2007

Wow. What a load of information to soak in. There is just so much to know regarding the gross anatomy of the brain that it makes my own brain tired. I read through the chapter, twice, and class was still hard for me. The professor (Dr. Greenwald) would show a slide and point to a place with his green laser pointer and say “okay, what’s this?” and alot of people would answer “hypothalamus” or “choroid plexus” or whatever it was he was pointing at. Me, well, I would just sit there and not answer for fear of being wrong. As it turns out, that was a good thing, because I would have been wrong over half of the time. But, Dr. Greenwald did mention that if you didn’t know this stuff now, that’s alright. We’re just getting started and all. Regardless, I still felt a bit lost.

Now, the meninges, on the other hand, I understood quite well, and it felt really good. For those of you who don’t know, the meninges are these layers that cover the outside of your brain and spinal cord. Three layers, actually. The first is a thin film that covers it directly. The second is a spider-webby-like structure that goes between the first and the third. The final layer is the Dura, this thick leathery stuff. Their main purpose is to provide structural support to the brain. You see, the brain is heavy, but left to gravity, it’d be pulled down into mush. The meninges allow it to float in Cerebrospinal Fluid, which goes between the first and second layers where all that spider-webby-stuff I mentioned earlier is. Just as you feel more lightweight in water, so your brain is also much less affected by gravity as it floats in this stuff. Fascinating.

Where things get really interesting is when fluid gets between those layers and the problems it can cause. For instance, if a legion occurs in the brain tissue and that blood gets between the second and third layer (say, you’re in a really bad car accident), then that blood (called hemorrhaging) can royally screw you. You see, something I just learned today is that blood is toxic to the brain. “Nothing kills brain cells faster than blood,” – Dr. Greenwald. Might be a slight over exaggeration, might not…I really don’t know at this point how much validity is in that statement. But one thing is for certain, and that is that blood is dangerous

The second interesting thing I learned today is that stem cells more often than not will turn into cancer cells. “When left to their own devices, they turn into cancer cells alot of times. I mean…why not?” – Dr. Greenwald. It seems so strange to me that there is such a controversy of stem cells when we as scientists haven’t even figured out a way to keep a majority of them from turning into cancerous cells, which are obviously harmful to the body. None doubt the power of stem cells when they work in our favor, but I have ready many articles on stem cells and I have never once heard about this. Truly interesting.

Anyone got any thoughts about any of this?