Sorry, in my studies, we refered to that as a direct inverse relationship.
Convoluted I know, but this is as opposed to an indirect inverse relationship. Again, sorry, getting way to technical.
As for how they are valued and priced, well I spent a semister studying Bond and equity Markets. It's complicated, but here is a good overview:
http://www.duke.edu/~charvey/Classes...al/bondval.htm