
Homeostasis refers to a system's ability
to regulate its INTERNAL environment.
The Big Bang Theory Season 6, Episode 2

At best you can say, "Hey, look, my idea
has an INTERNAL logical consistency."
The Big Bang Theory Season 1, Episode 3

The Internal Revenue Service
would strongly disagree.
The Big Bang Theory Season 2, Episode 18

(SIGHS) Can it be more of
an INTERNAL struggle?
The Big Bang Theory Season 10, Episode 7

It’ll be the INTERNAL medicine doctor,
won’t it? I don’t know.
Money Heist Season 1, Episode 13