So anyway, this week we learned some information about the somatic sensory system. Because of time constraints we didn't finish the whole chapter but we'll be completing it this week. Our time was limited because the VCR in our classroom decided to malfunction so we couldn't watch the entire video on touch in one sitting, so it carried over to the next class period. Then in lab our practice runs of our clinical neuroanatomy test took a bit longer then expected so we didn't have a lecture that day either. Our quiz ended up being on only a small amount of the text plus the Sacks reading which I found to be really interesting.
The first reading concerned a woman who lost her sense of proprioception, or in simpler terms, where her arms and legs were in relation to the rest of here body. Essentially she only knew where they were by looking at them, so as you can probably guess this made motor coordination virtually impossible. I never really thought of knowing where your limbs are in relation to the rest of your body as being an actual sense, but if you think about it, you unconsciously know where they are, otherwise you'd be constantly walking and banging into things. In fact you wouldn't be able to walk without looking at your feet, and then you couldn't see where you were going! Evetually through a lot of hard work and determination the woman learned how to function without this sense, but she still ran into a lot of difficulties as people did not understand what was wrong with her. It was not determined exactly what caused the woman to lose this sense, which is kind of scary.
Another interesting reading was on phantom limbs. Often people who lose a limb in an accident continue to feel sensations where there limb used to be. This is a very strange phenomenon which has only recently been proven to actually exist. Prior to this, physicans would tell their patients to go see a shrink. What I found to be surprising was that in order to use a prosthetic limb, the patient has to have a phantom limb. This actually makes a great deal of sense. If one did not have a phantom limb sensation and tried to use an artificial limb it would be very difficult, in fact it would probably be very similar to a person with two arms, trying to attach and use an artificial arm as a third arm. Because one does not normally have a third arm, one would have a very difficult time keeping track of where it was in relation to one's body. If, however, one has a phantom limb, it would be similar to reattaching the missing limb, which one still has a sense of, and can therefore exert some amount of control over the artificial limb.