Where does serratus posterior superior insert?

Where does serratus posterior superior insert?

• A. Superior border of ribs 2-4
• B. Inferior border of ribs 6-9
• C. Superior border of ribs 6-8
• D. Costal cartilage of ribs 1-2

Answer: (A)

The key idea is where serratus posterior superior attaches. This muscle runs from the lower part of the neck region to the upper back and inserts on the superior borders of the second to the fourth ribs, so it helps lift those ribs during inspiration. That’s why the correct option is the one describing the superior borders of ribs 2–4. The other described insertions belong to different muscles or regions (for example, the serratus posterior inferior attaches to the inferior borders of the lower ribs, and costal cartilage of ribs 1–2 isn’t the insertion for this muscle).

The key idea is where serratus posterior superior attaches. This muscle runs from the lower part of the neck region to the upper back and inserts on the superior borders of the second to the fourth ribs, so it helps lift those ribs during inspiration. That’s why the correct option is the one describing the superior borders of ribs 2–4. The other described insertions belong to different muscles or regions (for example, the serratus posterior inferior attaches to the inferior borders of the lower ribs, and costal cartilage of ribs 1–2 isn’t the insertion for this muscle).