what is the phrenic nerve
The phrenic nerve is a nerve that originates in the neck (C3-C5) and passes down between the lung and heart to reach the diaphragm.It is important for breathing, as it passes motor information to the diaphragm and receives sensory information from it.There are two phrenic nerves, a left and a right one. The right phrenic nerve passes over the brachiocephalic artery, posterior to the subclavian vein, and then crosses the root of the right lung anteriorly and then leaves the thorax by passing through the vena cava hiatus opening in the diaphragm at the level of T8. 2  The right phrenic nerve passes over the right atrium.