Skip to main content

Unfortunately we don't fully support your browser. If you have the option to, please upgrade to a newer version or use Mozilla Firefox, Microsoft Edge, Google Chrome, or Safari 14 or newer. If you are unable to, and need support, please send us your feedback.

Publish with us
Scalenus Medius Muscle
Muscular System

Scalenus Medius Muscle

Musculus scalenus medius

Read more

Quick Facts

Origin: Transverse processes of C2-C7 vertebrae.

Insertion: Superior surface of first rib.

Action: Laterally flexes neck; elevates first rib.

Innervation: Anterior rami of third to eighth cervical nerves (C3-C8).

Arterial Supply: Ascending cervical artery.

Complete Anatomy
The world's most advanced 3D anatomy platform
Try it for Free


The scalenus medius muscle arises from the transverse process of second cervical vertebra (axis) and the posterior tubercles of the transverse processes of the third to seventh cervical vertebrae (C3-C7). It commonly has an additional slip which attaches to the first cervical vertebra (atlas).


The scalenus medius muscle inserts into the superior surface of the first rib, specifically, between the tubercle of the rib and the groove for the subclavian artery.

Key Features & Anatomical Relations

The scalenus medius muscle is crossed anteriorly by the omohyoid muscle as it runs posteriorly towards the scapula. It is separated from the scalenus anterior muscle by the subclavian artery and the brachial plexus.


The scalenus medius muscle is involved in multiple actions:

- during unilateral contraction, it laterally flexes the neck to the same side at the cervical vertebral joints;

- it elevates the first rib and can act as an accessory muscle of inspiration (Standring, 2016).


Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.

Complete Anatomy

The world's most advanced 3D anatomy platform

Complete Anatomy