External Intercostals

• The Intercostals

  • Pass between adjacent ribs
  • 11 pairs between ribs 1 to 12 in the intercostal space
  • Arranged in 3 layers
  • Outer layer – external intercostals
  • Middle layer – internal intercostals
  • Deep layer – innermost intercostal
• Origin:

  • From the inferior border of the rib above

  A) external intercostals

  
• Insertion:

  • the superior border of the rib below

  A) external intercostals

  
• Direction:

  • Fibres run obliquely downwards and forwards

  A) external intercostals

  
• Action:

  • inspiration

  A) external intercostals