Structures

  • Deep transverse perineal muscle
  • External urethral sphincter
  • Compressor urethrae (Missing from atlas)
  • Urethrovaginal sphincter (Missing from atlas)
  • Bladder + Urethra (for orientation)
  • Ovaries, Fallopian tubes, Uterus + Vagina (for orientation)

MuscleActionOriginInsertionInnervationBlood supply
External urethral sphincter- Compresses the membranous urethra
- Relaxes during micturition
- Inferior ramus of the pubis on each side
- Adjacent walls of deep perineal pouch
- Surrounds membranous urethra- Perineal branches of the pudendal nerve: S2-S4- Internal pudendal artery
Deep transverse perineal- Stabilises the perineal body- Medial ischial ramus- Perineal body- Perineal branches of the pudendal nerve: S2-S4- Internal pudendal artery
Compressor urethrae (women only)- Accessory sphincter of the urethra- Ischiopubic ramus on each side- Right and left compressor urethrae blend anterior to the urethra- Perineal branches of the pudendal nerve: S2-S4- Internal pudendal artery
Sphincter urethrovaginalis (women only)- Accessory sphincter of the urethra
- Assists closing the vagina
- Perineal body- Passes forward lateral to the vagina to blend with partner on other side anterior to the urethra- Perineal branches of the pudendal nerve: S2-S4- Internal pudendal artery