《灵枢·经脉》：心主手厥阴心包络之脉，起于胸中，出属心包络，下膈，历络三焦。

The Chapter "Discussion on the Meridians" in Miraculous Pivot says: The Pericardium Meridian starts from the chest, and enters its pertaining organ, the pericardium. It descends through the diaphragm to connect successively with the upper, middle and lower energizer.

A branch arising from the chest runs inside the chest, comes out from the costal region below the axilla and ascends to the axilla. Following the medial aspect of the upper arm, it runs between the Lung Meridian and Heart Meridian to the cublital fossa, further downward to the forearm between the tendons of m.palmaris longus and m.flexor carpi radiadis, enters the palm, then passes along the middle finger right down to its tip.医学 全在.线提供www.med126.com

其支者：别掌中，循小指次指出其端。

Another branch arising from the palm runs along the ring finger to its tip.