to c6h603,
when you asked me,how does the pancreas differentiate between liver produced glucose and ingested carbs, it got me thinking as well.
i asked the question on another site and a very kind lady gave me this link.
http://www.geocities.com/m1physiolo...crine/endo5.htm

it also explains what happens duing exercise.
after reading it i came to the conclusion that we are a very complex piece of machinery!

christine