Quick Facts
Origin: Transverse processes of C4-T4 vertebrae.
Insertion: Mastoid process of temporal bone.
Action: Extends, rotates and laterally flexes head.
Innervation: Lateral branches of posterior rami of cervical and upper thoracic nerves.
Arterial Supply: Occipital, deep cervical, and vertebral arteries, dorsal branches of upper posterior intercostal arteries.
Related parts of the anatomy
Origin
The longissimus capitis muscle originates from the transverse processes of the fourth cervical to fourth thoracic vertebrae. There can be variations between individuals regarding the origin sites for the longissimus capitis muscle (Tubbs, Shoja and Loukas, 2016).
Insertion
The fibers of the longissimus capitis muscle travel superiorly along the posterior neck region and insert onto the posterior aspect of the mastoid process of temporal bone. There can be variations between individuals regarding the insertion sites for the longissimus capitis muscle (Tubbs, Shoja and Loukas, 2016).
Key Features & Anatomical Relations
In general, the longissimus muscles are the central-most muscles of the erector spinae. They are intrinsic muscles of the back and are found along the entire length of the back and posterior neck regions. They are long, flat skeletal muscles that are composed of three parts:
- longissimus capitis, which is the superior portion;
- longissimus colli, which is the middle portion;
- longissimus thoracis, which is the large, inferior portion.
The longissimus muscles are located:
- superficial to the ribs, and the external intercostal, levatores costarum breves, and levatores costarum longi muscles;
- deep to the sternocleidomastoid, splenius capitis, serratus posterior superior, rhomboid major, trapezius, latissimus dorsi, and serratus posterior inferior muscles, and the thoracolumbar fascia;
- medial to the iliocostalis muscle;
- lateral to the spinalis muscle.
Actions
The longissimus capitis muscle is involved in multiple actions:
- during unilateral contraction, it rotates the head to the same side at the atlantoaxial joints;
- during unilateral contraction, it laterally flexes the head to the same side at the atlantooccipital joints;
- during bilateral contraction, it extends the head at the atlantooccipital joints (Moore, Dalley and Agur, 2009).
References
Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2009) Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
Tubbs, R. S., Shoja, M. M. and Loukas, M. (2016) Bergman's Comprehensive Encyclopedia of Human Anatomic Variation. Wiley.
