ABSTRACT
The phrenic and vagus nerves on each side enter the thorax between the subclavian vein and subclavian artery, the vagus being more medial. The courses are then asymmetrical. The left phrenic nerve (18) passes inferiorly, on the pericardium of the left ventricle, before passing through the central tendon of the diaphragm. Both phrenics give motor supply to the diaphragm, as well as sensory supply to the pericardium, mediastinal and diaphragmatic pleura, and peritoneum underlying the diaphragm.
