I've experienced a discomfort rather like this in Biology courses. It usually comes from transplanting something that's unusual or bizarre onto myself (perhaps what Aum means by empathy). One example - there are frogs (or toads?) that carry their young tadpoles embedded in their skin while they developed. I imagined my cheek... oh god. Yeah. Alert, because it grosses me out.
I imagined by cheek wriggling with these, me scraping the layers off so that they could get out, leaving holes in my face.
This makes giving blood difficult as well,
because I imagine an air bubble growing in my vein, or hitting an artery...
As far as reactions to static parts, I could have little visceral twinges, but I think the only thing that ever made me react that way was the vas deferens, but my reaction wasn't as severe; I just felt uncomfortable. I think I got over it with time.
So I don't think you're that odd.