At the beginning of the second season, a longer intro was introduced that included all of the characters in the show, and not just the doctors. It was quickly scuttled when NBC decided to extend the length of the episodes in an attempt to win more viewers. See more
The x-ray with the show's title shown in the beginning is turned the wrong way: the heart should be seen on the right hand side. This was an intentional mistake put in by creator Bill Lawrence
to represent the core idea of the show: young doctors in over their heads. Bill Lawrence reminds viewers that this goof was completely intentional in interviews, DVD commentaries, and virtually any other available opportunity. See more
Well, gosh - I guess I became a doctor because ever since I was a little boy, I just wanted to help people. I don't tell this story often, but I remember when I was seven years old, one time I found a bird that had fallen out of its nest, and so I picked him up and I brought him home, and I made him a house out of an empty shoebox.
I became a doctor for the same four reasons that everybody does - chicks, money, power and chicks.