In total, there are 12 meridians on each side of the body: 3 yin meridians (heart, lung, and pericardium) and 3 yang meridians (small intestine, large intestine, and sanjiao) of the arm, 3 yin meridians (liver, kidney, spleen) and 3 yang meridians (urinary bladder, gall bladder, and stomach) of the leg.