Final answer:
The SJ primary channel, in traditional Chinese medicine, disperses from ST 12 downwards between the skin and muscles, relating to the San Jiao meridian's pathway for managing the body's vital energy.
Step-by-step explanation:
The SJ primary channel descends from ST 12 and disperses downwards between the layers of the skin and muscles. This refers to the pathway of one of the meridians used in traditional Chinese medicine, specifically related to the San Jiao (Triple Burner) meridian. The dispersal of this channel's energy flow is critical for maintaining balance within the body's qi, or vital energy. The San Jiao meridian is associated with multiple physiological functions and plays an important role in the traditional Chinese medicinal framework for understanding health and disease.