All are true about sphincter urethrae except
The urethral sphincter is two muscles used to control the exit of urine in the urinary bladder through the urethra. Two muscles either the female or male, external urethral sphincter and internal urethral sphincter. ref - BDC vol2 pg376,380
Voluntary
Supplied by Pudendal nerve
Originates from the ischiopubic rami
Located at bladder neck
Abdomen and pelvis