system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 26-year-old woman presents to the obstetrics ward to deliver her baby. The obstetrician establishes a pudendal nerve block via intravaginal injection of lidocaine near the tip of the ischial spine. From which of the following nerve roots does the pudendal nerve originate?
assistant
S2-S4