Answer
Fig. 20.2
Veins are subjected to less pressure than arteries, and therefore need less elasticity.
Work Step by Step
Both the large elastic conducting arteries, and the distributing arteries have much more elastic tissues than veins in general-- though there is some elastic tissue in the tunica media of medium veins. The elastic tissue in conducting arteries enable them to expand as they receive blood during the ventricular systole, and to recoil during the ventricular diastole. The expansion prevents extreme pressure from damaging smaller arteries downstream and also stores some of the energy of the systole. The recoil releases the stored potential energy slowly and maintains the bloop pressure at a healthy level as the ventricular pressure falls during diastole.