Jamel loves to climb mountains and hike long distances. He prefers to pack light, and often opts for an energy bar. It is a glucose-based confection flavored with peppermint. It provides Jamel with 9.5 g of carbohydrates per 10 g serving. Because he is often gone for long periods of time, he always makes sure that he packs the right foods for his trips. What roles do the digestive, circulatory, and respiratory systems play in the way that Jamel's body will use the energy bar?