Muscle
External intercostals
Elevate ribs (inspiration)
High-yield
Fibres run "hands in pockets"; elevate ribs in inspiration. Intercostal nerves (T1-T11).
Overview
Eleven pairs of muscles between the ribs whose inferomedial fibres elevate the ribs during inspiration.
Reference facts
- Origin
- Inferior border of the rib above
- Insertion
- Superior border of the rib below
- Action
- Elevate the ribs, increasing the thoracic cavity in inspiration
- Innervation
- Intercostal nerves (anterior rami of T1-T11)
- Blood supply
- Posterior and anterior intercostal arteries
Frequently asked questions
What does the external intercostals do?
The external intercostals elevate the ribs, increasing the thoracic cavity in inspiration.
What nerve innervates the external intercostals?
The external intercostals is innervated by the intercostal nerves (anterior rami of T1-T11).
Where does the external intercostals attach?
The external intercostals originates from the inferior border of the rib above and inserts on the superior border of the rib below.
What is the blood supply of the external intercostals?
The external intercostals is supplied by the posterior and anterior intercostal arteries.