Asker's rating. 1  Fred is correct the smaller the number the bigger the metal. 2  12 gauge is thinner than 7 gauge. 3  The gague refers to the thickness of the metal in question. the issue of strenght is really determines by the type of metal, not necessarily it's thickness.
The left ventricle pumps oxygen-rich blood out of the heart and into an artery called the aorta. From the aorta, blood branches out into a series of ever smaller tube-like vessels: arteries, arterioles and finally capillaries. The capillaries deliver the blood's oxygen and nutrients to cells.
The pulmonary arteries take blood into the lungs, where it is oxygenated. From there, oxygenated blood travels back to the left side of the heart through the pulmonary veins, at which time it enters the left atrium. From the left atrium, blood flows through the mitral valve into the left ventricle.