This door theoretically led to another sickbay ward identical to this one.  
It was thought that we might see a character exit this ward through this 
door, then we might see that character enter the "second" ward through 
the door on the opposite end of this set.  Although this was never done, 
we did get a glimpse of this "second" ward in the back window of Beverly's 
office in the Star Trek: Generations feature film.  During the first season of 
Star Trek: The Next Generation, this door was also the door from the 
Conference Lounge back to the bridge, since during those early episodes 
the sickbay and the conference lounge were redresses of the same set.  Æ