The cremasteric reflex is elicited by stimulating the proximal inner thigh and causes elevation of the testicle on the same side. The reflex tests which nerve?

• A. Genitofemoral
• B. Femoral
• C. Obturator
• D. Iliohypogastric

Answer: (A)

The test is about the genital branch of the genitofemoral nerve, which supplies the cremaster muscle and carries the reflex arc for the cremasteric response. When the proximal inner thigh is stroked, sensory information travels to the spinal cord at the L1–L2 level, and the motor response is to contract the cremaster muscle via the genital branch of the genitofemoral nerve, pulling the testicle upward on the same side. So this reflex specifically evaluates the integrity of the genitofemoral nerve pathway. The other nerves listed do not control the cremaster muscle’s reflex pathway.