Factual paragraphs

Every few chapters, the author includes a factual paragraph about things, such as "Look closely at the skin on your writs. The blue lines are arteries..." I wonder why the author chose to do this, most of these chapters have little or nothing to do with the rest of the book. I thought that maybe the author wanted to foretell what was going to happen later in the novel, but I checked the book for that and that idea didn't make sense. I think that these paragraphs should have been left out because they just take up space.