Why is the interaction a frog's digestive and circulatory system important for its survival?
The circulatory system circulates blood around the body. The blood passes through the lungs, where it loses carbon dioxide and gains oxygen. All cells need oxygen to function and carbon dioxide is a form of waste produced in the cells.
The digestive system breaks down food and absorbs nutrients which the body needs for survival. These nutrients are absorbed into the blood and then circulated to all the cells of the body by the circulatory system.
Thus, the circulatory system and the digestive system interact in two important ways. First, the circulatory system makes the products of digestion (absorbed food) available to the rest of the body. Second, the circulatory system brings the organs of the digestive system the oxygen they need to keep functioning, while also carrying away waste. The frog needs both systems functioning together in order to survive.