From my experience-->
NursingCAS uses the transcripts you send them to verify GPA and actual courses taken, usually takes a week or two for them to calculate GPA. You should err on the side of caution and send an extra transcript to the programs / universities you plan to apply toward. Nursing CAS I believe breaks down your GPA, one for sciences, and one overall. The nursing school you applied to does not receive that information electronically per say, they have a username and password which allows them to access applications off of Nursing CAS. You have to pay the Nursing CAS fee that is required and ensure that they have your transcripts, because it will take time to process GPA calculations.
Pardon my quick typing :l , I used NursingCAS back for Fall of 2011.