A study of the cardiac innervation in domestic animals: Cattle

Abstract

Abstract The cardiac innervation of cattle was morphologically dissected and described. Descriptions of the ganglia of origin as well as the course and distribution are presented. Sympathetic nerves arose from the thoracic and cervicothoracic ganglia, but unlike those of the horse, dog and cat did not arise from the more cranial situated cervical ganglia. Most left thoracic and some cervicothoracic cardiac nerves passed through a cardiac ganglion of the left intervascular triangle before being distributed to the heart. Parasympathetic cardiac innervation arose from the vagi, both cranial and caudal to the origin of the recurrent laryngeal nerve, and from the recurrent laryngeal nerves themselves. Left heart nerves primarily supplied the area along the coronary groove caudally and on the right side. This included the area of the coronary sinus and atrioventricular node. Left cardiac nerves also extended along the right coronary artery. Both left and right cardiac nerves passed to the cardiac plexus and also along the descending and circumflex branches of the left coronary artery on the left side. Right cardiac nerves extended primarily between the venae cavae or between the caudal vena cava and left atrium to the area of the sinoatrial node but also into the area of the coronary sinus and atrioventricular node.