Figure 5 below is a diagrammatic representation of the heart. a) i. Identify structure X. [ 1 ] ii. Explain the function of structure Y. [2] b) Explain how the structure of the heart allows for the efficient pumping of [ 8] blood around the body to deliver oxygen to, and collect carbon dioxide from, the body tissues. c) Describe three ways in which the structure of each of capillaries, veins and [9] arteries are adapted to carry out their functions..