Longus Capitis Muscle Anatomy

The longus capitis is a prevertebral muscle situated in the anterior region of the cervical spine. This paired muscle demonstrates a complex architectural arrangement, extending from the basilar portion of the occipital bone to the anterior tubercles of the transverse processes of the third through sixth cervical vertebrae (C3-C6).

The longus capitis develops from the ventral masses of the cervical myotomes, specifically from the hypaxial portions of the cervical somites. This developmental origin explains its deep position and intimate relationship with the cervical vertebrae.

Longus Capitis Muscle Anatomy

The Longus Capitis muscle originates via four tendinous slips from the anterior tubercles of the transverse processes of C3 through C6 vertebrae. Each slip forms a discrete muscular fascicle that travels superiorly and medially. The muscle inserts into the inferior surface of the basilar part of the occipital bone, specifically in the depression anterior to the foramen magnum. This strategic positioning enables the muscle to exert precise control over cranial movements.

The longus capitis muscle receives its primary innervation from the anterior rami of spinal nerves C1 through C4, with particularly significant contributions from C1-C3. This rich neural input reflects the muscle’s importance in fine motor control of head movements. The arterial supply primarily derives from branches of the inferior thyroid artery and the ascending cervical artery, ensuring adequate blood supply for this deeply situated muscle.

See Also: Brachial Plexus Anatomy Overview

The longus capitis demonstrates several crucial functions in head and neck biomechanics. When acting bilaterally, it facilitates anterior flexion of the head and upper cervical spine, contributing to the nodding motion of the head. Unilateral contraction results in ipsilateral flexion and slight rotation of the head toward the same side. Additionally, the muscle plays a vital role in stabilizing the head during various movements and maintaining proper cervical lordosis.

Clinical Relevance

The muscle’s deep location makes it susceptible to involvement in cervical spine pathologies, including cervicogenic headaches and cervical spondylosis. Furthermore, its anatomical relationship with surrounding structures, such as the longus colli muscle and the sympathetic trunk, makes it an important consideration in anterior cervical spine approaches and diagnostic imaging interpretation.

References & More

1. Clinically Oriented Anatomy, 8th Edition https://shop.lww.com/Clinically-Oriented-Anatomy/p/9781975154090
2. Gray’s Anatomy: The Anatomical Basis of Clinical Practice, 42nd Edition https://www.elsevier.com/books/grays-anatomy/standring/978-0-7020-7710-5
3. McDavid LJ, Khan YS. Anatomy, Head and Neck, Prevertebral Muscles. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: Pubmed