In the supraclavicular area, posterior to the superior border of the clavicle and at its midpoint, 4 cun lateral to the midline, on the mamillary line, which point is this?

• A. ST 10
• B. ST 11
• C. ST 12
• D. ST 13

Answer: (C)

The question tests your ability to translate surface landmarks into the exact point on the stomach channel in the supraclavicular region. The specified location—posterior to the clavicle’s superior border, at its midpoint, 4 cun lateral to the midline on the mamillary line—maps to the stomach channel point that sits in the supraclavicular fossa, behind the clavicle. That point is ST12. It is the only point in this precise spot described by these landmarks, which is why this is the correct identification. Nearby points describe different positions (either higher in the neck or further along the chest wall) and do not match this combination of landmarks.