The splenius muscles are: *

Splenius capitis muscle The splenius capitis () () is a broad, straplike muscle in the back of the neck. It pulls on the base of the skull from the vertebrae in the neck and upper thorax. It is involved in movements such as shaking the head. Structure It arises from th ...

Splenius cervicis muscle The splenius cervicis () (also known as the splenius colli, ) is a muscle in the back of the neck. It arises by a narrow tendinous band from the spinous processes of the third to the sixth thoracic vertebrae; it is inserted, by tendinous fasciculi, ...

Their origins are in the upper thoracic and lower cervical

spinous process The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

es. Their actions are to extend and ipsilaterally rotate the head and neck.

References

Muscles of the torso {{Muscle-stub