What to propel blood through the vessel shown here? what to propel blood through the vessel shown here? the large size of the lumen contraction of the smooth muscle in the tunica media contraction of surrounding skeletal muscle stretching and recoil of elastic fibers in the vessel wall?

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.