The heart meridian of hand-shaoyin originates from the heart and absorbs qi of the spleen meridian of foot-taiyin. There are three trunks begins from heart. The first arises from heart, running downward aorta blood vessel and passing through disphragmatic muscle, it is distributed over small intestine. The second trunk arises from heart and is divided into two branches, ascending throat along two sides of esophagus and passing through upper hupeh to fossa orbitalis, it is distributed over the back side of eyeball, passing through collateral of brain and is associated with brain. The third trunk also arises from heart; the upper line is divided into two branches which are above lung and runs along left and right clavicle to lateral side of rib, the lower line runs down to oxter and comes out to upper limb, passing posterior biceps brachii to flexor surface of ulnar of elbow joint, it runs down elbow joint along flexor surface of ulna to microcephaly of ulnar of wrist. Coming through the fourth and the fifth metacarpal bones, it reaches tip of little finger along radial side of little finger and associates small intestine meridian of hand-taiyang, which links with qi of small intestine meridian of hand-taiyang.

Collateral of Heart meridian of hand-shaoyin:
Originating from Tongli acupoint of heart meridian of hand-shaoyin at 1cun behind wrist, arising two branches from here, the first branch curves around to dorsal side of ulna and is associated with meridians in internal and external relation of small intestine meridian of hand-taiyang, forming intercommunication gangway of qi of meridians in internal and external relation, the second goes along heart meridian of hand-shaoyin and passes ulnar border which is at anterior aspect of elbow joint and posterior biceps brachii to oxter, penetrating into chest below collarbone, it is distributed over heart.

Ascending along both sides of esophagus from heart to both sides of throat, it is distributed over tongue. The trunk ascends to fossa orbitalis and is distributed over posterior eyeball, penetrating into collateral of brain, it is associated with brain. Heart meridian of hand-shaoyin is distributed over eye system; therefore, collateral of heart meridian of hand-shaoyin is associated with heart meridian of hand-shaoyin here and its branch is associated with small intestine meridian of hand-taiyang.

Collateral of heart meridian of hand-shaoyin which is a special distribution of collateral is distributed over internal organs and organs of head as divergent collateral and forms the connection in parallel from heart meridian of hand-shaoyin to heart, eye, and brain, it associates small intestine meridian and forms connection in parallel of collateral.

Divergent collateral of heart meridian of hand-shaoyin:
Originating from heart meridian of hand-shaoyin which is between pectoralis major and latissimus dorsi below oxter, ascending along heart meridian of hand-shaoyin to chest, it is distributed over heart. Forking from heart, ascending along both sides of artery to both sides of throat, it comes out of face and runs obliquely up to medial angle of eye and connects with meridians in internal and external relation - small intestine meridian of hand-taiyang here, it forms the fourth combination in "six combinations" and intercommunication gangway of qi of meridians in internal and external relation.