What are the intercostal muscles?

The muscles between the ribs is called the intercostal muscles. Gray's Anatomy (1918) describes it as two layers of thin muscles — external and internal intercostals — filling the spaces between adjacent ribs.

What it is

  • Two layers of thin muscles — external and internal intercostals — filling the spaces between adjacent ribs.
  • Elevate and depress the ribs during breathing.
  • Help stiffen the chest wall.

Where it is

  • Between each pair of ribs, on both sides of the chest.
  • Extend from the vertebral column behind to the sternum in front.
  • Run in different directions in each layer.

Source:

Last verified: 2026-07-18

  • Best Anatomy Answers is an educational reference about human anatomy. It is not medical advice — for any health concern, talk to a licensed medical professional.

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