USMLE High-Yield Questions on Instagram: "“spinal cord said ABSOLUTELY NOT” ⸻ 📚 EXPLANATION (WITH ANSWER) An unexpected stimulus to the perianal region causes an immediate, involuntary contraction of the external anal sphincter. This is the anal wink reflex. • Reflex arc: pudendal nerve • Spinal cord levels (afferent + efferent): S2–S4 👉 Correct answer: D) S2–S4 ⸻ ❌ WHY THE OTHERS ARE WRONG A) T12–L1 ❌ Abdominal wall sensation; not anal sphincter reflex B) L1–L2 ❌ Cremasteric ref