I asked a surgeon friend of mine if he knew a good mechanic.

“Yeah. Me,” he said. “I pretty much fix my own car. Why don’t you just fix your own car? You’re pretty handy. Do it yourself!”

“Too complicated,” I told him.

“Whadday talking about?!” he said. “The gut. The heart. The kidneys. Those are complicated machines. A car engine or a boat engine? Much simpler!”

I looked at him, disbelieving.

“Think about it,” he said. “If I can cut out dead gut, then reconnect it, I can figure out how to fix my car. If you can figure out a heart, you can figure out a stupid engine!"

OK, so he had a point. But then I remembered the last time I decided I was going to fix my broken chainsaw. I took it apart,"fixed it," then put it back together. But when I looked at my workbench, there were three screws, a spring, a rubber thing, and a mysterious metal rod that I didn’t remember taking out but that were left over. Which, I suppose, is a lot better than leaving something like a sponge inside someone’s chest when doing a pacemaker. All the same, I had a fallen tree across my driveway and needed that chainsaw.

As engines go, the human body is fascinating. Just think about the gut for a second. All of us interact with it (and some of us are obsessed with) on a daily basis. The machinery of the gut is not at all shy about telling us when trouble’s a-brewing. It whines, gurgles, squeaks, cramps, toots, and even blasts when it needs attention. How cool is it that the gut can differentiate between solid, liquid and gas and let each one pass in turn. Well, most of the time. I still remember having a severe case of gastroenteritis while working as a doctor in the mountains of Peru. A gas cramp became a dangerous gamble — to let it out did not carry good odds at all.

I have a friend who loves cars. He calls Car and Driver magazine “car-porn”; he loves hot rods and revving motors. Me? Not so much. I only change the oil in my truck because the light comes on and nags me to do it. I’ve had the “fix engine light” on for about a month now, and the thought of sitting in a mechanic’s room waiting for it to be fixed is about as appealing as getting a colonoscopy. At least during a colonoscopy I get to sleep.

The heart, on the other hand, now THAT is one sexy machine. Today I got to read echocardiograms — ultrasound pictures of the heart beating. A healthy heart looks as coordinated, graceful and pretty as the winning couple on “Dancing with Stars.” A diseased heart, by contrast, looks like a middle-aged white guy dancing at a wedding after he’s had too many Manhattans. (OK, I admit it, I am that guy, and unfortunately there is video somewhere that proves it.)

The point of engines is that you really have to take good care of them. Ignoring your car’s maintenance will quickly turn your vehicle into an old klunker. The body’s engine is no different, except that you can change a car, but you only get one body.