external urethral sphincter

Origin

• internal surface of ischiopubic ramus & ischial tuberosity

Insertion

• surrounds urethra
• in males, ascends anterior aspect of prostate
• in females, some fibers also enclose vagina (urethrovaginal sphincter)

Innervation

• deep branch of perineal nerve, a branch of pudendal nerve (S2, S3, S4) Main action:
• compresses urethra to maintain urinary continence
• in females, urethrovaginal sphincter portion also compresses vagina

More general terms

• skeletal muscle (voluntary muscle)

Additional terms

• perineum
• urethral sphincter