It is. They're what hold back
the URINE and feces.
The Big Bang Theory Season 8, Episode 18
It took me a gallon of URINE
to make that water.
The Big Bang Theory Season 5, Episode 15
He was so busy figuring out
how many parts per million of URINE...
The Big Bang Theory Season 8, Episode 9
Howard Hughes saved his URINE
in milk bottles.
The Big Bang Theory Season 10, Episode 23
What you're buying here
are the ingredients for very expensive URINE.
The Big Bang Theory Season 1, Episode 4