External intercostal muscles
Musculi intercostales externi
Definition
The external intercostal muscles (Musculi intercostales externi) occupy the intercostal spaces superficially from ventral extent of levator costarum to costochondral junction, and do not extend as far as the sternum like the internal intercostal muscles. The fibers of the external intercostal muscles are orientated perpendicular to the ones of the internal intercostal muscles.
In dogs:
Origin: caudal border of ribs
Insertion: cranial border of rib below
Action: inspiration, to draw the ribs together so as to enlarge the thoracic cavity
Nerve: Intercostal nerves one to twelve.
References
Miller's Anatomy of the Dog, 4th Edition - Evans & de Lahunta- Elsevier Illustrated Veterinary Anatomical Nomenclature - 3rd edittion - Gheorghe M. Constantinescu, Oskar Schaller - Enke
