Splenius cervicis muscle
Splenius cervicis is a paired back muscle found in the prevertebral space of the neck. Together with splenius capitis, it forms the superficial layer of the deep (intrinsic) back muscles, thus covering the other deep back muscles in the cervical region of the back.
The function of the splenius cervicis is to coordinate the position of the head and neck during various body movements, such as standing up from a sitting position. It does so by producing the lateral flexion, rotation and extension of the neck.
This article will discuss the anatomy and function of splenius cervicis muscle.
|Origin||Spinous processes of T3 – T6 vertebrae|
|Insertion||Transverse processes of C1 – C3 vertebrae|
|Action||Unilateral contraction: lateral flexion and rotation of neck (ipsilateral)
Bilateral contraction: extension of neck
|Innervation||Lateral branches of posterior rami of lower cervical spinal nerves|
|Blood supply||Vertebral, occipital, superior intercostal, deep cervical, transverse cervical arteries|
Origin and insertion
Splenius cervicis is a paired, flat bow-shaped muscle in the posterolateral aspect of the neck. It originates from the spinous processes of thoracic vertebrae T3-T6. The obliquely oriented muscle fibers initially travel superolaterally then curve medially to insert on the tubercles of transverse processes of cervical vertebrae C1-C3.
Like the other deep neck muscles, splenius cervicis is invested in the deep layer of deep cervical fascia. It is found superficial to semispinalis capitis and longissimus capitis, and deep to sternocleidomastoid and trapezius muscles. Splenius cervicis courses along the inferolateral margin of splenius capitis and blends almost indistinguishably with it.
Splenius cervicis muscle is innervated by the lateral branches of the posterior rami of the lower cervical spinal nerves.
The arterial blood supply to this muscle arises from:
- Vertebral artery
- Deep cervical artery
- Descending branch of occipital artery
- Transverse cervical artery
- Superior intercostal artery
The venous drainage of splenius cervicis mimics its arterial supply.
Unilateral contraction of splenius cervicis causes ipsilateral lateral flexion and rotation of the neck. However, when contracting bilaterally, this muscle aids the trapezius muscle to extend the neck.
The neck extension produced by this muscle has an important function during standing up from a sitting position, as it puts the neck into a stance from which the longus capitis can bring the head into the neutral position once the body’s upright.
Take a look at our video to understand the anatomical concepts of different body movements.