Pudendal nerve block involves?
High-Yield Explanation
ANSWER: (D) S2 S3 S4REF: Morgan 3rd ed p. 331. Essentials of Pain Management - Nalini Vadivelu, Richard D. Urman, Roberta L. Hines Page 428, Grant's atlas of anatomy - Page 270"Pudendal nerve block involves S2 S3 S4"The pudendal nerve innervates the lower vagina, perineum, and vulva. Block of this nerve can be used to supplement pain relief during the second stage of labor. The S2-S4 nerves give off branches to the pudendal nerve that pass between the pyriformis and coccygeal muscles. The nerve is blocked at the pudendal canal, just lateral and inferior to the sacroaspinous ligament. A pudendal nerbe block does not abolish sensation from anterior and lateral part of perineum and hence a block of ilioinguinal and/or posterior cutaneous nerve of thigh may also be required.