The left side pumps the same volume against greater peripheral resistance, so the left ventricular walls are more muscular. There is functional specialisation in the vessels too. The branches are always smaller than the trunk and so on. Several branches may come off at a single level, but more often a main trunk gives off branches and continues. Structure is also graded as you pass away from the heart.
Large trunks have much elastic tissue in their walls.
Repeated distention and contraction of this tends to even out heart contractions into a steady, though pulsatile flow. Smaller branches have less elastic tissue and more smooth muscle offering better control of flow to suit temperature, activity etc. Resistance vessels Control blood flow at more intimate level - muscular arterioles and precapillary sphincters provide principle resistance to blood flow which governs pressure in arterial tree. Exchange vessels Capillaries are often composed of a single wrapped cell at any given level. Across their walls occurs exchange between blood and tissue fluids, oxygen, CO2, nutrients, water, inorganic ions, vitamins, hormones, metabolic products, immune substances, even immune competent cells.