Henry Gray (18251861). Anatomy of the Human Body. 1918.
The right nerve is situated more deeply, and is shorter and more vertical in direction than the left; it lies lateral to the right innominate vein and superior vena cava.
The left nerve is rather longer than the right, from the inclination of the heart to the left side, and from the diaphragm being lower on this than on the right side. At the root of the neck it is crossed by the thoracic duct; in the superior mediastinal cavity it lies between the left common carotid and left subclavian arteries, and crosses superficial to the vagus on the left side of the arch of the aorta.
Each nerve supplies filaments to the pericardium and pleura, and at the root of the neck is joined by a filament from the sympathetic, and, occasionally, by one from the ansa hypoglossi. Branches have been described as passing to the peritoneum.
From the right nerve, one or two filaments pass to join in a small phrenic ganglion with phrenic branches of the celiac plexus; and branches from this ganglion are