Which nerve provides innervation to Serratus posterior superior?

Which nerve provides innervation to Serratus posterior superior?

• A. Intercostal nerves T6-T9
• B. Long thoracic nerve
• C. Dorsal scapular nerve
• D. Intercostal nerves T2-T5

Answer: (D)

The serratus posterior superior is supplied by the ventral rami of the upper intercostal nerves, specifically the second through fifth intercostal nerves. This matches its location and attachments to ribs 2–5 and its role in aiding rib elevation during inspiration. The long thoracic nerve goes to serratus anterior, not this muscle, so it wouldn’t innervate SPS. The dorsal scapular nerve supplies rhomboids (and sometimes levator scapulae), not the serratus posterior group. Nerves innervating lower intercostal levels (the lower ribs) don’t align with the SPS’s rib attachments, so they wouldn’t provide its motor supply.

The serratus posterior superior is supplied by the ventral rami of the upper intercostal nerves, specifically the second through fifth intercostal nerves. This matches its location and attachments to ribs 2–5 and its role in aiding rib elevation during inspiration. The long thoracic nerve goes to serratus anterior, not this muscle, so it wouldn’t innervate SPS. The dorsal scapular nerve supplies rhomboids (and sometimes levator scapulae), not the serratus posterior group. Nerves innervating lower intercostal levels (the lower ribs) don’t align with the SPS’s rib attachments, so they wouldn’t provide its motor supply.