^ This is true.
I remember thinking how wacky that seemed to me at the time. There's this little room with an airlock, the bridge's bathroom, a security office, etc right behind the bridge... but seemingly no direct way of accessing it
. Until, yes you're right, I finally noticed that the port turbolift has got a second door. Apparently.
I seen people claim that you can actually see
an interior door at the back of the Enterprise D's portside turbolift in a few season 1 episodes, but I've never spotted it myself. Anybody else seen it?