Phrenic Nerve

The Phrenic nerve arises from C3 - C5. It is formed at the superior lateral portion of the scalenus anterior and courses to its medial border. It is located in the prevertebral fascia. It is crossed anteriorly by the suprascapular and transverse cervical arteries. The right phrenic nerve lies on the lateral aspect of the venous channel of the right heart. The left phrenic nerve is crossed by the thoracic duct, which joins the bifurcation of the left brachiocephalic vein. It is motor to the diaphragm and sensory to the parietal pleura and the parietal peritoneum covering the diaphragm.

Severance of the phrenic nerve results in paralysis of the corresponding half of the diaphragm.