Right phrenic nerve

Nervus phrenicus dexter

NervousNervesWhole bodyRight side

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What it is
Arises mainly from C4 (with C3 and C5) in the neck, runs straight down on the front of the anterior scalene muscle, enters the chest between the subclavian artery and vein and descends over the fibrous pericardium in front of the lung root to the diaphragm. The right nerve runs on the brachiocephalic vein, superior vena cava and right atrium and reaches the diaphragm beside the inferior vena cava.
Function
The only motor nerve to its half of the diaphragm (the main breathing muscle); also carries sensation from the central diaphragm, pericardium and mediastinal pleura.
Size
About 2 mm thick; ~30 cm long
Clinical note
Irritation under the diaphragm is felt as shoulder-tip pain (C4 dermatome). A paralysed phrenic nerve - after heart surgery, from a lung tumour or after an interscalene block - leaves one hemidiaphragm high on the chest X-ray.

Part of Cervical plexus

Nearby nervous structures Accessory nerve (CN XI), Brachial plexus, Cardiac plexus, Left phrenic nerve, Left recurrent laryngeal nerve, Left vagus nerve (CN X), Right recurrent laryngeal nerve, Right vagus nerve (CN X), Spinal cord, Spinal dura mater (dural sac)