This brings up the question of whether those pocket doors are pressure-proof. We see standard cabin doors supposedly act as a barrier against the dikironium cloud in "Obsession", but physically these are flimsy structures, rather easily forced by Khan, and lacking in anything that would resemble an airtight threshold.
In TNG, the interior doors are clearly just "cardboard", brushing against carpeting, stopping nothing, and blown out of their hinges by the impact of a body thrown about. In ENT, there's lots of heavy metal there to suggest the exact opposite. Where does TOS fit in between these two?
We see those curious A-frames on various corridor locations aboard Kirk's ship. Scissoring pressure doors that swing in place under the failure-proof gravitic pull of the floor? The rest of the interior between such doors might be a single pressure vessel, any doors therein serving only "decorative" purposes.
It's a bit worrisome, then, that the turbolift doors appear to be much the same as the cabin doors. Is the entire shaft network open to ambient air / breach vacuum?