Suboccipital

The suboccipital nerve (first cervical dorsal ramus) is the dorsal primary ramus of the first cervical nerve (C1). It exits the spinal cord between the skull and the first cervical vertebra, the atlas. It lies within the suboccipital triangle along with he vertebral artery, where the artery enters the foramen magnum. It supplies muscles of the suboccipital triangle, the rectus capitis posterior major, obliquus capitis superior, and obliquus capitis inferior. The suboccipital nerve also innervates rectus capitis posterior minor.

The cervical plexus is formed by the ventral rami of the upper four cervical nerves and the upper part of fifth cervical ventral ramus. the network of rami is located deep to the sternocleidomastoid within the neck. the cervical plexus innervates muscles of the neck and areas of skin on the head, neck and chest. the deep branches innervate muscles, while the superficial branches supply areas of skin. a long branch (primarily of fibers of c4 and with contributions of fibers from c3 and c5; nervus phrenicus) innervates muscles of the diaphragm. the cervical plexus also communicates with the cranial nerves vagus nerve and hypoglossal nerve.