Posterior Rami of Cervical Nerves (Left)

Description

The posterior (dorsal) rami of the cervical nerves are one of the two terminal branches of the first to eighth cervical nerves, the others being the anterior (ventral) rami.

The posterior rami are mixed nerves conveying both sensory and motor information to and away from the central nervous system. Postganglionic sympathetic fibers also travel inside the posterior rami.

The posterior ramus of the first cervical nerve (or suboccipital nerve), emerges above the posterior arch of the atlas and enters the suboccipital triangle. It provides motor innervation to muscles around the suboccipital triangle and sensory innervation from the meninges and atlantooccipital joint.

The posterior ramus of the second cervical nerve is the largest of all cervical posterior rami. It emerges between the posterior arch of atlas and the lamina of the axis and winds underneath the obliquus capitis inferior muscle before dividing into medial (greater occipital nerve) and lateral terminal branches. The former provides motor innervation to obliquus capitis inferior and semispinalis capitis muscle and sensory innervation to scalp and dura mater in the posterior cranial fossa. The lateral branch provides motor innervation to longissimus capitis, semispinalis capitis, and splenius capitis.

The posterior rami of third to eighth cervical nerves (C3—C8) all run posteriorly around their respective articular pillars and provide motor innervation to various muscles including semispinalis capitis, multifidus, interspinalis, longissimus colli, splenius colli and iliocostalis colli muscles. In addition, sensory innervation is provided to the facet joints above and below the nerve and the skin around the medial back region.