There is no integration between the image gallery feature and other features other than you can browse to the images and use them in other content.
Our Html Content feature does have a built in slide show that can treat any top level html element in the content as a slide, and as mentioned in that article in the section "CSS Class for Slide Container div" it tells how you can make just part of the content into a slide show by wrapping the images in a div with a custom css class you can make only the elements within that div become slides while the surrounding content is not. However this only works in the Html Content feature not in blog posts.
Hope that helps,
Joe