The obturator nerve (L2–L4) passes through the obturator foramen and divides into anterior and posterior divisions. Which muscle does the POSTERIOR division of the obturator nerve innervate that is NOT innervated by the anterior division?
- A Obturator externus ✓
- B Adductor longus
- C Gracilis
- D Pectineus
Explanation
The obturator nerve divides into anterior and posterior divisions as it passes through the obturator foramen. The anterior division innervates adductor longus, adductor brevis, gracilis, and gives a sensory branch to the medial thigh. The posterior division passes through and innervates obturator externus (a lateral rotator of the hip), then continues to supply adductor magnus (adductor portion — the hamstring part is innervated by the sciatic nerve). Obturator externus is the distinctive muscle innervated only by the posterior division. Pectineus is innervated primarily by the femoral nerve (and sometimes accessory obturator).
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.