A 40-year-old woman with a perforated duodenal ulcer develops sudden severe epigastric pain followed by pain referred to the tip of the shoulder. Which nerve carries the afferent limb of this referred pain?

• A Intercostal nerves T7 to T11
• B Phrenic nerve C3, C4 and C5 ✓
• C Subcostal nerve T12
• D Genitofemoral nerve L1 and L2

Explanation

The central part of the diaphragmatic peritoneum, which lies directly over the leaked gastric contents, is supplied by the phrenic nerve roots B3, B4 and B5. These same roots form the supraclavicular nerves supplying the skin over the shoulder tip, so irritation of the central diaphragm is perceived as shoulder pain. The peripheral diaphragmatic peritoneum is supplied by lower intercostal nerves and refers pain to the lower chest and flank instead, which kills that distractor.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.