C22 - Plexus sacralis

Question 1

Define plexus sacralis

Answer 1

• Plexus lumbalis + plexus sacralis = plexus lumbosacralis
  
  • Ventral branches of the cranial sacral nerves form plexus sacralis, whixh joins the ventral branches of the last three lubar spinal nerves to form plexus lumbosacralis
• Plexus sacralis extends distally in the wall of the pelvic cavity as the sciatic plexus. It gives origin to:
  
  • N. gluteus cranialis
  • N. gluteus caudalis
  • N. cutaneous femoris caudalis
  • N. pudendus
  • N. rectalis caudalis
• The sciatic plexus continues as n. sciaticus after the detachment of these branches
• Supplies:
  
  • Caudal muscles of the thigh
  • Skin

Question 2

Give the sacral part of the lumbosacral plexus

Answer 2

• The sacral part of the lumbosacral plexus extends distally in the wall of the pelvic cavity
• They have 2 main destinations:
  
  • Leaves the pelvis via for. sciaticus major
  • Remain in the pelvis

Question 3

Give the sciatic plexus

Answer 3

• The sciatic plexus is an extension of the lumbosacral plexus, and continues as n. sciaticus
• N. sciaticus leaves the pelvis through greater sciatic foramen
• Proximal at femur, it divides into:
  
  • N. peroneus communis
    
    • Detatches n. cutaneus surae lateralis
    • Divides into:
      
      • ​N. peroneus superficialis
      • N. peroneus profundus
  • N. tibialis
    
    • ​Detatches n. cutaneus surae caudalis
    • Terminal division:
      
      • N. plantaris medialis
      • N. plantaris lateralis

Question 4

Draw plexus lumbosacralis

Answer 4