Splenius capitis muscle

The splenius capitis muscle is a wide muscle in the back of the neck that connects the base of the skull and several upper vertebrae. It tilts the head backward when contracted.

Origin
The splenius capitis originates from the first, second, and third thoracic vertebrae, T1-T3. It attaches to the spinous processes of T1-T3, the supraspinous ligament above these vertebrae, and the lower portion of the nuchal ligament.

Insertion
The splenius capitis inserts at the superior end to the mastoid process on the temporal bone of the skull.

Action
Unilateral contraction of the splenius capitis leads to an extension of the head while bilateral contraction leads to rotation and ipsilateral bending of the head.

Innervation
The splenius capitis muscle is innervated by the dorsal rami of the third and fourth cervical spinal nerves.

Blood supply
The splenius capitis muscle receives blood through the muscular branches of the aorta.

Word origin
The name splenius capitis comes from splenius, Greek for bandage, and capitis, Latin for head.