While a patient was being given an obstetric nerve block she gradually lost her voluntary control over urination. The muscle which got anaesthetized is located in the: (A) Trigone of the bladder, (B) Urogenital diaphragm, (C) Superficial perineal pouch, (D) Pelvic diaphragm
Answer is B. The urogenital diaphragm contains the external urinary sphincter & deep transversus perinei muscle which is responsible for voluntary control over urination. In its blockade, the voluntary control over micturition will be lost.