I'm a fan of anatomy. Anatomy hasn't changed in many years. There are new discoveries and understanding of the human body but overall it's constant.
There are many fascinating things about our body. How our body temperature is regulated. Our ability to push our physical limits and come back stronger. How the brain (a 3 pound mass in your head) controls and coordinates every bodily function.
Unlike a machine, the more we use our bodies the better it gets. We see this with exercise, sports, even mental endeavors. If you don't use it you loose it.
Our body is amazing. Seemingly unconnected things like good posture and heart function are linked. I've always wondered, why do our ears keep growing throughout our lives? Your ear will be one inch longer when you reach 100!
If you're interested in exploring anatomy, I found a website that offers a very comprehensive look at human anatomy, it's called www.visiblebody.com and it's free.