Which of the following nerves is derived from the dorsal primary rami of spinal nerves?
The greater occipital nerve is a branch of the dorsal primary ramus of spinal nerve C2. It provides cutaneous innervation to the posterior scalp. None of the other listed nerves are dorsal primary rami. The great auricular nerve comes from the C2 and C3 branches in the cervical plexus; It provides sensory innervation to the ear and the skin below the ear. The lesser occipital nerve also comes from C2 in the cervical plexus. It innervates the skin behind the ear. The phrenic nerve is comprised of contributions from the ventral primary rami of C3, C4, and C5. It innervates the diaphragm. The supraclavicular nerves come from C3 and C4 in the cervical plexus. These cutaneous nerves provide sensory innervation to the skin of the root of the neck, upper chest, and upper shoulder. Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 25. Overview of the Neck. In D.A. Moon, K.B. Foreman, K.H. Albeine (Eds), The Big Picture: Gross Anatomy.
Great auricular
Greater occipital
Lesser occipital
Phrenic