During a posterior approach to the kidney, the surgeon encounters a muscle in the posterior abdominal wall that is innervated by the ventral rami of L1, L2, and L3. Which muscle is this?
- A Quadratus lumborum
- B Iliacus
- C Psoas major ✓
- D Transversus abdominis
Correct answer: C. Psoas major
Explanation
Psoas major is innervated by ventral rami of L1-L3. Quadratus lumborum is innervated by T12-L4. Iliacus is innervated by the femoral nerve (L2-L4). Transversus abdominis is innervated by the lower six thoracic nerves and L1. This distinction is frequently tested in posterior abdominal wall anatomy questions.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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