Semispinalis

Description

Posterior neck and upper thoracic back anatomy is presented with the deep transversospinalis layer exposed, centered on semispinalis capitis and semispinalis cervicis in a male. Semispinalis fascicles ascend superomedially from thoracic and lower cervical transverse processes toward the occipital bone, lying deep to splenius capitis and trapezius and lateral to the cervical spinous processes. The cervical vertebrae are shown with clear spinous and transverse processes, and the occipital part of the skull forms the superior attachment zone near the nuchal lines. Segmental organization is emphasized. Semispinalis capitis is a primary extensor of the head and an ipsilateral rotator, and its deep position makes it a key landmark when teaching layered posterior neck dissection. Clinically, this region is approached during posterior cervical exposure and suboccipital dissection, where careful identification and detachment near the occipital insertion helps protect the greater occipital nerve as it emerges between inferior obliquus capitis and semispinalis capitis, a common anatomic basis for occipital neuralgia and post-surgical dysesthesia. The cervicis portion also contextualizes cervical stability and the mechanics of extension moments across multiple vertebral segments rather than at a single joint. Use this plate in gross anatomy labs, neuromuscular anatomy lectures, and spine surgery teaching materials to clarify how semispinalis runs parallel to the vertebral axis and how its fibers relate to cervical bony landmarks used for level identification. It also fits well in textbooks and patient-facing surgical consent materials discussing posterior cervical approaches and cervicogenic headache anatomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.