Muscle
Anterior scalene
Key neck landmark
High-yield
Phrenic nerve lies on its anterior surface; subclavian artery and brachial plexus pass between anterior and middle scalenes (interscalene triangle).
Overview
A deep lateral neck muscle that elevates the first rib and flexes the neck; the phrenic nerve descends on its surface and the brachial plexus/subclavian artery pass behind it.
Learning this group? Read How to learn the brachial plexus.
Reference facts
- Origin
- Transverse processes of C3-C6
- Insertion
- Scalene tubercle of the first rib
- Action
- Elevates the first rib in inspiration; laterally flexes and rotates the neck
- Innervation
- Anterior rami of C4-C6
- Blood supply
- Ascending cervical / inferior thyroid arteries
Clinical correlation
Compression in the interscalene triangle underlies thoracic outlet syndrome.
Frequently asked questions
What does the anterior scalene do?
The anterior scalene elevates the first rib in inspiration; laterally flexes and rotates the neck.
What nerve innervates the anterior scalene?
The anterior scalene is innervated by the anterior rami of C4-C6.
Where does the anterior scalene attach?
The anterior scalene originates from the transverse processes of C3-C6 and inserts on the scalene tubercle of the first rib.
What is the blood supply of the anterior scalene?
The anterior scalene is supplied by the ascending cervical / inferior thyroid arteries.