SP-21 is located on the mid-axillary line in which intercostal space?

SP-21 is located on the mid-axillary line in which intercostal space?

• A. On the mid-axillary line, in the seventh intercostal space
• B. On the mid-axillary line, in the sixth intercostal space
• C. In the depression at the centre of the axilla
• D. On the anterior chest wall

Answer: (A)

SP-21 sits on the side of the chest along the mid-axillary line. To find it, use the vertical mid-axillary line that runs down from the outer edge of the armpit. Intercostal spaces are numbered from the top, so the seventh intercostal space is the gap between the seventh and eighth ribs. SP-21 is located at that level along the mid-axillary line, on the lateral chest wall. This places the point lower on the chest compared with points nearer the front, matching its position on the spleen channel.

SP-21 sits on the side of the chest along the mid-axillary line. To find it, use the vertical mid-axillary line that runs down from the outer edge of the armpit. Intercostal spaces are numbered from the top, so the seventh intercostal space is the gap between the seventh and eighth ribs. SP-21 is located at that level along the mid-axillary line, on the lateral chest wall. This places the point lower on the chest compared with points nearer the front, matching its position on the spleen channel.