On the second season of Nurse Jackie, one thing is clear: the writers have perfected each character.

Don't get me wrong, I loved the first season of this Showtime hit. But Jackie was the central focus of the first set of episodes (for good reason, of course). Now, as evidenced by "Apple Bong," the show has expanded to include a truly fascinating, multi-layered set of individuals. To wit:

Gloria Akalitus was a bumbling baffoon last year. Last night? She played the role of understanding mentor and friend to Jackie.

Zoey Barkow was one of the funniest characters on TV last year. Last night, and this season to date? She still makes us laugh, but she's evolved from a one-note, naive nurse to someone with multiple moods and stoylines... and she might be pregnant?!? Think we've met the baby daddy? I really hope it's not Lenny.

Eleanor O'Hara was just Jackie's snarky confidant last season. Last night? She finally got some (way to go, doc!) and she's been more front and more center over these first four episodes than ever before.

Dr. Fitch Cooper was an arrogant, hilarious jerk last season. Okay, not much about him has changed... but thank goodness! Coop would absolutely use Twitter and brag about his followers to co-workers. We have also seen a more human side to him, though. Jackie does overstep her boundaries as a nurse and it's not wrong of Coop to take issue with that.

As for Eddie? We just knew him as the guy that boned Jackie everyday at noon last season. He's now a more fully developed, and slightly psychotic character.

But it makes sense, doesn't it? He's a dude scored. The best part of he and Kevin's friendship? We have no idea where it's going. But we don't foresee anything positive on the horizon for Jackie.

What did you think of the episode? We've listed our favorite Nurse Jackie quotes from it below.

Coop: I almost have 1,000 Twitter followers now.
Zoey: Is that a lot?
Coop: Heck yeah! | permalink

Thor: I'm not in recovery. But I should be, for wedding cake addiction. | permalink

Gloria: I'm not a prude! I was at Woodstock for Christ's sake.
Jackie: No you weren't. | permalink

Eddie: You have a lot of pent-up anger.
Jackie: You have no idea. | permalink

Jackie: My house? My kids? Are you out of your f**king mind? | permalink

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.