Semispinalis capitis

Semispinalis capitis
Section of the neck at about the level of the sixth cervical vertebra. Showing the arrangement of the fascia coli. (Semispinalis capitis visible at bottom right.)
Deep muscles of the back. Semispinalis muscles labeled. Semispinalis capitis is the upper of the labeled ones.
Latin	musculus semispinalis capitis
Gray's	subject #115 400
Origin	Transversal process of lower cervical and higher thoracal columna
Insertion	Area between superior and inferior nuchal line
Artery
Nerve	Greater occipital nerve
Actions	Extend the head

The Semispinalis capitis (Complexus) is situated at the upper and back part of the neck, deep to the Splenius, and medial to the Longissimus cervicis and capitis.

It arises by a series of tendons from the tips of the transverse processes of the upper six or seven thoracic and the seventh cervical vertebræ, and from the articular processes of the three cervical above this.

The tendons, uniting, form a broad muscle, which passes upward, and is inserted between the superior and inferior nuchal lines of the occipital bone.

The medial part, usually more or less distinct from the remainder of the muscle, is frequently termed the Spinalis capitis; it is also named the Biventer cervicis since it is traversed by an imperfect tendinous inscription.

It lies deep to the trapezius muscle.

The semispinalis muscles are innervated by the dorsal rami of the cervical spinal nerves.

Additional images

• 

  Occipital bone. Outer surface.

• 

  Base of skull. Inferior surface.

External links

• SUNY Figs 01:06-01
• SUNY Figs 24:01-01
• Duke Orthopedics semispinalis_capitis_1
• lesson6musclesofback at The Anatomy Lesson by Wesley Norman (Georgetown University)

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.