Intermediate Layer

• Serratus posterior superior
  • Bony Attachments:
    • 1. Ligamentum nuchae, SP C7-T3
    • 2. Ribs 2-5 beyond rib angle
  • Innervation: T1-T4 spinal nerves
  • Arterial Supply: Post. intercostal a.
  • Action: Raises the upper ribs
• Serratus posterior inferior
  • Bony Attachments:
    • 1. Thoracodorsal fascia
    • 2. Ribs 9-12
  • Innervation: T9-T12 spinal nerves
  • Arterial Supply: Post. intercostal a.
  • Action: Depresses the lower four ribs