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External intercostal
Other Terms:
Musculi intercostales externi,
Musculus intercostalis externa,
Muscle intercostaux externes
Muscle parts
None
Latin name
Musculi intercostales externi
Latin muscle parts
None
Group
Thoracic wall – lateral musculature – external layer
Etymology
In English, this muscle’s name is the outward muscle between the ribs. The word intercostal comes from the Latin terms inter meaning “between” and costa meaning “rib.”The Latin term externus means “outward.”
Origin
Inferior border of superior rib
Insertion
Superior border of adjacent inferior rib
Action
Stiffen the chest wall to prevent paradoxical motion during descent of the diaphragm; move the ribs.
Nerve supply
Intercostal nerves (T1 through T11)
Blood supply
Anterior intercostal arteries from the internal thoracic artery via the subclavian artery. Superior intercostal artery from the costocervical trunk of the subclavian artery. Posterior intercostal arteries from the aorta. Superior and lateral thoracic arteries from the axillary artery, along with branches from the pectoral branch of the thoracoacromial artery.
Latin
Musculi intercostales externi
Latin
Musculus intercostalis externa
French
Muscle intercostaux externes