Anterior scalene

The anterior scalene (Latin: musculus scalenus anterior) is a muscle of the neck located in its lateral aspect. Therefore, this muscle is one of the lateral neck muscles. Together with the middle and posterior scalene muscles, it is classified as the scalene muscle. The anterior scalene lies behind the sternocleidomastoid.

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Anterior scalene muscle by Anatomy Next
Anterior scalene muscle
OriginAnterior tubercles of transverse processes of C3 - C6 vertebrae
InsertionSuperior border and anterior scalene tubercle of first rib
Action

Unilateral contractions - neck lateral flexion (ipsilateral), neck rotation (contralateral), elevation of first rib

Bilateral contractions - neck flexion

Innervation Anterior rami of 4th to 6th cervical spinal nerves (C4 - C6)
Blood supplyAscending cervical artery

Origin

The anterior scalene muscle originates from the anterior tubercles of the transverse processes of the 3rd to 6th cervical vertebrae (C3 - C6).

Insertion

The insertion site of the anterior scalene is the superior border and anterior scalene tubercle of the first rib.

Action

By contracting on both sides, the anterior scalene muscle flexes the neck. By contracting on one side, it bends the neck laterally to the same side (ipsilateral). Also, unilateral contractions provide contralateral neck rotation and elevation of the first rib.

Innervation

The anterior scalene is innervated by the anterior rami of the 4th to 6th cervical spinal nerves (C4 - C6).

Blood supply

The anterior scalene muscle receives arterial blood supply from the ascending cervical branch of the inferior thyroid artery.