The zàng-fǔ organs are functional entities stipulated by Traditional Chinese medicine (TCM). They constitute the centre piece of TCM's general concept of how the human body works. The term zàng (脏) refers to the organs considered to be yin in nature – Heart, Liver, Spleen, Lung, Kidney – while fǔ (腑) refers to the yang organs – Small Intestine, Large Intestine, Gall Bladder, Urinary Bladder, Stomach and Sānjiaō.