Dynamic Picture, Dynamic Text

I’m writing an application that I’d like to work in the following way:

Across the bottom will appear thumbnails with invisible buttons. When you click on one of the thumbnails (invisible buttons) the image is loaded in a loader. In the full size picture, I’d like to be able to hover over sections of the picture and have text updated. The problem is, I’m not sure how to approach it since I’ll have about 6 pictures, and each picture would have several ‘hotspots’ in which to hover over and update text. Some of the text would be lengthy.

Please advise.