Pelvic Anatomy 6

Question 1

What do the parasympathetics do in the UG system?

Answer 1

• Urination
• Defecation
• Erection
• Utrine cervical galnds

Question 2

What do the sympathetics do in the UG system?

Answer 2

• Mostly for “tubes”:
  
  • arteries
  • ureters
  • ductus (vas) deferens for ejaculation
  • bladder trigone
    
    • internal urethral sphincter

Question 3

What does the somatic innervation supply in the UG system?

Answer 3

• Supplies both the pelvic and urogenital diaphragms:
  
  • levator ani
  • external urethral sphincter
  • transverse perineal muscles
• Supplies anal sphincter
• Supplies musclces in the superficial perineal pouch

Question 4

Where do the autonomic nerves come from in the UG system?

Answer 4

• Pelvic plexus (inferior hypogastric plexus)
  
  • receives visceral sensory neruons (for uterus) and sympathetics from the superior hypogastric plexus
    
    • continuation of aortic plexus
• Pelvic splanchnic nerves (from S2, 3, 4)
  
  • parasympathetics and visceral sensory to all viscera (except uterus)

Question 5

Where does somatic innervation come from in the UG system?

Answer 5

• Pudendal nerve
  
  • nerve of the perineum body wall
  • formed from the ventral rami of sacral spinal nerves S2, 3, 4
  • Passes out of greater sciatic foramen into the lesser sciatic formaen to get to the pelvic body wall structures below the levator ani
    
    • loops over the ischial spine and sacrospinous ligament