Nurse Carla Espinosa

Carla is the head nurse at Sacred Heart, and the person who actually knows how the hospital runs. She's tough, warm, and fiercely competent, with zero patience for the doctors' egos and adolescent games — especially J.D.'s. She's also dating Turk, and clearly done waiting around for him to grow up.

Judy Reyes plays Carla as the show's ballast: funny without being a punchline, sharp-tongued but never brittle. The writing lets her call out male foolishness without turning her into a scold, and Reyes gives her a warmth underneath the bluntness that makes her advice — medical or otherwise — feel earned rather than nagging.