Diaphragm: Phrenic nerve, which arises from fourth cervical chiefly; lower intercostals, especially eighth and ninth; and phrenic plexus of the sympathetic which may sometimes be reached from the fourth or fifth dorsal vertebrae through the gangliated cord. For motor disturbances of the diaphragm adjust fourth cervical.
Abdominal Muscles: These are supplied by the lower intercostals and the transversalis and internal oblique make connection with L 1 by the iliohypogastric. Cremaster is supplied by L 1 and 2 by way of the genital branch of the genitofemoral.
Perineal Muscles: The anterior perineal group are supplied by the perineal branch of the internal pudic which traces to the second, third, and fourth sacral nerves. The posterior perineal and ischiorectal region is also supplied by the sacral and coccygeal nerves.
Trachea and Bronchi: Vagus and sympathetic filaments from first and second thoracic ganglia. The latter receive preganglionic fibres from first dorsal nerve in all probability, as this adjustment reaches the bronchi.
Lungs: The third thoracic ganglia connect with the pulmonary plexus and establish a connection from third dorsal vertebra direct to the lung parenchyma. The Pleurae have a similar connection or may sometimes be reached by the first dorsal.
Heart and Pericardium: In 55% of all heart disease or improper action the second dorsal is responsible; in 40% the first dorsal, and perhaps in the remaining 5% the atlas or axis. The former nerves (T 1 and 2) furnish pre-ganglionic fibres which stream upward through the gangliated cord to terminate in the three cervical ganglia in relation with the dendrites of new neurons (amyelinic) which form the superior, middle, and inferior cardiac nerves and pass into the thorax to mingle with vagal fibres to form the superficial and deep cardiac plexuses, controlling the heart. Probably the upper cervicals occasionally affect the vagus through the loop between the first and second cervical nerves.
Thoracic Aorta: Controlled by sympathetic from first thoracic ganglion or last cervical ganglion, and thus by seventh cervical or first dorsal vertebra.
Abdominal aorta—Coeliac Axis: The upper portion of the abdominal aorta is innervated by the coeliac or solar plexus of the sympathetic. Sub-plexuses from the coeliac accompany the various branches of the aorta and are widely distributed to the blood-vessels and to the glands and non-striated muscle of the abdominal organs. The coeliac plexus receives fibres from the right vagus and from the greater, lesser, and least splanchnic nerves, by the latter route making connection with the thoracic ganglia of the sympathetic from fifth to last. These ganglia receive pre-ganglionic fibres from the thoracic spinal nerves in the form of white rami communicantes, so that it is not incorrect to say that the coeliac plexus and its branches are largely controlled by the condition of the last eight thoracic nerves.
Through this intricate plexus it is difficult to trace the relations of each abdominal organ with the particular vertebrae of which subluxation would produce disease in said organ. By the aid of clinical experimentation covering a period of years and by diligent search among anatomies and physiologies, we have arrived at the conclusions indicated in succeeding statements.