In Star Trek: Insurrection movie, there was this funny conversation:
Deanna Troi: Have you noticed how your boobs have started to firm up?
Beverly Crusher: Not that we care about such things in this day and age.
Deanna Troi: Uh-huh.
[notices Data]
Beverly Crusher: Thank you, Data.
[Data walks up to Worf]
Worf: I have an odd craving for the blood of a live Kolar beast. This environment must be affecting me again.
Data: And have you noticed how your boobs have started to firm up? Not that we care about--
I am interested in the first sentence of the above conversation. I guessed that it has something to do with being young again, but what exactly was Troi talking about? Which biological phenomenon?