This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Inferior Cardiac Nerve, called also the cardiacus minor, usually arises from the inferior cervical ganglion, very often from the first thoracic ganglion. The middle and inferior cardiac nerves communicate freely with branches from the recurrent.
There are some differences between the cardiac branches of the right and left sides: viz., the middle cardiac nerve of the left side receives its principal branch from the inferior cervical ganglion; and very frequently on this side the middle and inferior cardiac nerves are united into a single trunk. The cardiac branches of the pneumogastric nerve of the right side are usually three or four in number, and arise from their parent trunk about an inch above the origin of the common carotid artery; they are lost in the cardiac filaments of the inferior cervical ganglion. The pneumogastric nerve of the left side generally sends off only a single twig, which runs on the front of the arch of the aorta and enters the neighboring cardiac plexus.
The cardiac plexuses are three in number,—the great, the superficial or anterior, and the deep or posterior. The first is seen in front of the trachea and above the right pulmonary artery, and behind the arch of the aorta ; it is formed principally by the middle and inferior cardiac nerves of both sides. The second is situated upon the front of the aorta, close to its origin, and may be exposed by removing the serous layer of the pericardium from this vessel: branches from the great cardiac plexus, from the superior cardiac nerves, and from the cardiac ganglion, enter this plexus. The third is situated, immediately behind the origin of the aorta.
The cardiac ganglion of Wrisberg, when present, is situated underneath the arch of the aorta, and is in contact with that part of the concavity of the artery which lies to the right side of its connection with the ductus arteriosus: the superior cardiac nerves of the right and left sides, together with filaments from the pneumogastric nerves, enter into its formation. The cardiac branches of the recurrent nerve are pretty numerous, and unite with the cardiac branches of the pneumogastric and great sympathetic.
The anterior and posterior coronary plexuses are branches derived from the cardiac plexuses, which accompany the coronary arteries and their branches.
The Lymphatics Of The Heart consist of a superficial and a deep set: the superficial set form a net-work under the serous layer of the pericardium; the deep set ramify between the endocardium and muscular fibres ; and both of them follow the coronary vessels. Some of them unite with the lymphatics of the lung, and others terminate in the lymphatic glands in front of the arch of the aorta and pulmonary veins.