Technically confused about Normal maps

I've been trying to get this pipe mesh have a bumpy appearance. I was able make the mesh itself pretty bumpy but by doing that my poly count skyrockets and it's terrible for my game. So I tried normal mapping it using the texture and normal map below. Here's what I did: I created a bump diffuse shader then plopped in the texture and normal map but I'm getting nothing.

Am I supposed to do some sort of UV Mapping in blender before I bring in my model? Is there a way I can just pattern this texture across my vein? How can I make A look like B without adding so much poly?

I apologize I'm not very technical and have a hard time understanding he relationships between normal mapping and uv mapping if there is one.