According to TCM, the small intestine meridian influences mental clarity, judgment, and discernment. Functionally, it controls digestion and elimination. It is also thought to influence the pituitary gland, which controls immunity, metabolism, sexuality, and endocrine function.
In total, there are 19 points on the small intestine meridian. The meridian starts on the little finger and follows the edge of the hand to the wrist, where it turns slightly to flow up the forearm, close to the outer edge of the ulna. Passing the elbow at the ulnar nerve (funny bone), it continues up the back of the arm, behind the shoulder joint. It then curves across the shoulder blade to connect with the governing vessel at GV-14, as do all yang channels.
The channel then crosses forward to the hollow area above the collarbone where the internal branch penetrates, first to the heart, then along the esophagus to the stomach, before connecting with its own organ, the small intestine. From the collarbone region, the superficial path continues up behind the muscle on the side of the neck (sterno-cleido-mastoid), then over the cheek to the ear. Two internal branches separate on the cheek, leading to the gallbladder channel on the outer corner of the eye, and to the bladder channel at BL-1 on the inner corner.