As one of the five zang-organs, the heart is located in the thorax above the diaphragm and enveloped by the pericardium. It is primarily involved in governing the blood and vessels as well as housing the mind. Since its two functions play significant roles in all activities of life, the heart is regarded as the “monarch of all the organs,” “root of life,” and “great governor of five zang- organs and six fu-organs.” It pertains to fire in terms of five elements and relates to summer qi; therefore, it is yang within yang. It opens into the tongue, manifests its conditions in the luster of the face and associates with sweat in fluids and joy in emotions. It connects the Heart Meridian of Hand-shaoyin which has an interior-exterior relationship with the Small Intestine Meridian of Hand-taiyang.