Tip

• The superior gluteal nerve originates from the L4, L5, and S1 roots.
  • Gluteus medius, gluteus minimus, tensor fascia latae
  • thigh/hip abduction
• The inferior gluteal nerve arises from L5, S1, and S2.
  • Gluteus maximus
  • Thigh/hip extension
• The posterior cutaneous nerve comes from S1, S2, and S3.
• The pudendal nerve is derived from S2, S3, and S4.
• The sciatic nerve, being the largest, includes roots from L4 to S3.
• Obturator nerve
  • thigh adduction

Iliohypogastric nerve

Obturator nerve

Pudendal nerve

• Motor innervation
  • External urethral sphincter
  • External anal sphincter
  • Levator ani muscles
  • Bulbospongiosus muscle
  • Ischiocavernosus muscle
• Sensory innervation
  • Inferior rectal nerves
    • Skin of the perianal region
    • Lower third of the anal canal
  • Perineal nerves
    • Skin of the perineum
    • Dorsal scrotum (men) or labia majora (women)
  • Dorsal penile (men)/clitoral (women) nerve
    • Dorsum of the penis/clitoris skin
    • Responsible for penile reflex erection
• Pudendal nerve block: injection of a local anesthetic into the pudendal canal to block transmission within the pudendal nerve
  • Most commonly used during childbirth prior to an episiotomy or during surgical procedures involving the perineum
  • The ischial spine is used as a landmark for injection.

Femoral nerve

*Can’t do those ↑