Where is the SI-19 acupuncture point located?

The SI-19 point, also known as "Ting Gong," is specifically located in the deep depression between the middle of the tragus and the mandible's condyloid process. This precise anatomical position is crucial for accurate acupuncture treatments targeting the small intestine meridian, which runs along this area.

Understanding this location is vital, as it allows practitioners to effectively access the point for various therapeutic interventions, including issues related to the ears, jaw, and facial region. The tragus is a notable landmark in acupuncture, and its relationship with adjacent structures, such as the mandible, helps ensure proper needle placement.

The other choices do not align with the established anatomical location of SI-19. The dorsal aspect of the head of the ulna is related to wrist and forearm acupuncture points, while the groove of the anterior border of the ulna pertains to different meridian lines. The outer canthus refers to the corner of the eye, which is not associated with the small intestine meridian but rather pertains to other points in facial acupuncture. Hence, the selection of option A reflects a clear understanding of SI-19's location along the small intestine meridian pathway.