Friday, February 05, 2010

Science at the doctor

I'm not fond of going to the doctor. In fact I hate it. I generally don't go unless I've got a pretty serious problem.

Recently, I've been having some pretty serious problems with my large to on my right foot; It keeps getting ingrown.

Last September, I visited a podiatrist and had the nail dug out. Now, 4 months later, it's grown out and went right back to being ingrown. So I headed back.

But this time, I had a better idea what to be expecting, and teaching a biology and chemistry course, there were several things that caught my interest more than they had last time.

The first one was a cool little spray the doctor used on my toe before shooting me full of Novocaine. This time, I asked him what exactly it was. He told me it was a "topical refrigerant" called Ethyl Chrloride. It's similar to spilling a bit of rubbing alcohol on your skin in that it feels cold due to heat from your body transferring into it and being carried off by evaporation. But Ethyl Chloride does this even more. It's like having supercooled water poured on you.

For my Chemistry class, I was told that the students were having some trouble understanding heat and temperature so I've been looking for some cool demonstrations for this to highlight the concept when we get back there (when we hit endothermic and exothermic reactions). I'd love to get some of this to talk about the transfer of thermal energy. Unfortunately, it's apparently used as a recreational drug, which is probably going to make it somewhat hard to get a hold of. Blast.

Another interesting side topic from my trip to the doctor had to do with Biology. In my Bio II class, we've been talking about prokaryotes and just finished a section on bacterial infections. Part of that included the methods by which they do damage. The book listed two: Actually destroying cells by using them as food, and releasing toxins that disrupt the homeostasis of other cells.

I had a minor infection going along with my nail and I'd noticed one of the effects was that the skin was peeling off in layers. I asked my podiatrist what was causing this and he pointed out that it was due, not to either of the effects our textbook listed, but to swelling caused by the bacteria stretching the skin past its elastic limit. This was a great bit of personal experience to bring into the classroom. A bunch of high school boys like nothing better than a good gross-out story. If only I had pictures....

I've also been somewhat interested in how my movement following my visit has been playing out. Obviously, I can't put much weight on my toe, so I've been having to walk more on the outside of the foot. It seems like a small shift, but it takes an entirely different type of movement. I was on my feet for 5 hours teaching after visiting the doctor yesterday, and then a few more for my weekly SCA night. Very quickly muscles were protesting. I haven't had time to look at it too carefully, but I suspect having to change my walk even this slightly is exercising slightly different muscle groups that almost never get use. They're protesting this morning.

While I still hate having to go to the doctor, occasionally, there's some cool stuff to learn there.

Science is everywhere.


Planeten Paultje said...

Been there. Had the sides of my left toe nail completely cut away. Surgeon said: You'll be just a few days. Turned out to be a few weeks and a lot of bleeding before I was in full swing again.

Jupiter said...

"I'd love to get some of this to talk about the transfer of thermal energy."
Here in Aus, the Wart freezing systems use something like that.
It would be an expensive way of obtaining it though, because you don't get much for $15
You get the cooling from the phase transition and further expansion of the liquid as it sprays out of the container and then more cooling as it boils off.
If you do it outdoors in a safe place with no flames, you can do it with an lpg cylinder - maybe get a CO2 cylinder ?

RBH said...

I'm coming late to this, but your mention of muscles aching due to changing your movements on account of the toe reminds me of how Dizzy Dean lost his mojo as a pitcher. The story goes that he broke a toe, tried to come back too soon and changed his pitching motion to favor the toe which in turn injured his arm so he lost his fastball.