Learning 3D in Photoshop

I'm taking my 2nd class at Seton Hall U. this semester. It is "Digital Art and Design". Our professor just left on maternity leave, I'll miss her the class was fun. And I wish her all my best. I met our new professor yesterday in class and he's already pushing me. This is a good thing. He really seems to know the programs and wants us to push hard in to learning more then just "burn and doge". Our first project is to make a poster on a part of the body. Something you would see in the Dr.'s office waiting room. This sounded fun at first. Then sounded way to involved. Then after a few hours of thinking about it, I came around. This could be fun. And it is going to be VERY challenging. I like that. I need to be pushed or I'll just float along.

Here are my first tries at creating a 3D effect.