Semispinalis Capitis (Musculus semispinalis capitis)
Educational content only — not medical advice.
Anatomy
A broad, powerful muscle forming the principal muscular bulk in the nape of the neck, situated deep to splenius and trapezius. It originates from the transverse processes of the upper six or seven thoracic vertebrae and articular processes of the lower four cervical vertebrae, ascending vertically to insert into the occipital bone between the superior and inferior nuchal lines. It acts as the primary extensor of the head and is pierced by the greater occipital nerve.
Origin & insertion
From the transverse processes of T1–T6 (or T7) and the articular processes of C4–C7, into the squamous part of the occipital bone between the superior and inferior nuchal lines.
Action
Extends the head and neck; unilaterally tilts the head and rotates the face slightly toward the contralateral side.
Innervation
Greater occipital nerve and posterior rami of cervical spinal nerves (C1–C5).
Clinical notes
Entrapment of the greater occipital nerve as it pierces the semispinalis capitis produces occipital neuralgia (Arnold neuralgia), causing paroxysmal stabbing pain radiating to the vertex.
Related structures
Educational references
FAQ
What is the role of the Semispinalis Capitis?
A broad, powerful muscle forming the principal muscular bulk in the nape of the neck, situated deep to splenius and trapezius. It originates from the transverse processes of the upper six or seven thoracic vertebrae and articular processes of the lower four cervical vertebrae, ascending vertically to insert into the occipital bone between the superior and inferior nuchal lines. It acts as the primary extensor of the head and is pierced by the greater occipital nerve.
Why is the Semispinalis Capitis clinically important?
Entrapment of the greater occipital nerve as it pierces the semispinalis capitis produces occipital neuralgia (Arnold neuralgia), causing paroxysmal stabbing pain radiating to the vertex.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details