I believe so, yes. There is an immediate response between going from being dormant to say wrestling a worm to eat as well. Blood starts coursing through their gills as their muscles need it for movement, they subsequently swell as a result. As the stomach needs blood for digestion, I've noticed they usually stay large for some time after feeding. If they don't get enough nutrition (iron + trace minerals) in their diet the size of gill tissue may diminish over time to the point where they don't really swell much during feeding anymore. Though I am no expert in cardiovascular functions in amphibian physiology -this is just what makes sense to me and partially witnessed first hand.