Splenius cervicis

The splenius cervicis (Latin: musculus splenius cervicis), also known as the splenius colli, is a paired long and relatively thin deep muscle of the back that is located in the back of the neck. It stretches between the spinous processes of the thoracic vertebrae and transverse processes of the cervical vertebrae. Together with the splenius capitis, the splenius cervicis lie in the superficial layer of the deep back muscles.

Origin

The splenius cervicis muscle originates from the spinous processes of the third to sixth thoracic vertebrae (T3 - T6).

Insertion

The fibers of the splenius cervicis insert on the posterior tubercles of the transverse process of the first to third cervical vertebrae (C1 - C3).

Action

Muscle contractions on both sides (bilateral contractions) extend the neck. Muscle contractions on one side (unilateral contractions) rotate and lateral flex the neck to the same side (ipsilateral).

Innervation

The splenius cervicis is innervated by the dorsal rami of the lower cervical spinal nerves that arise from the cervical plexus.

Blood supply

The splenius cervicis muscle receives arterial blood supply mainly from the occipital, transverse cervical and deep cervical arteries. The occipital artery arises from the external carotid artery, the transverse cervical artery is a branch of the thyrocervical trunk, while the deep cervical artery originates from the costocervical trunk.