DISSECTING M AXIAL. 



Superficial Cardiac Plexus. This lies in the hollow of the 

 aortic arch, superficial to the pericardium, and contains a small 

 ganglion (of Wrisberg). It receives the left inferior cervical 

 cardiac branch of the vagus, and left superior cervical car- 

 diac branch of the sympathetic superior cervical ganglion. 

 Branches pass between the aortic arch and pulmonary artery 

 bifurcation to the deep cardiac plexus, along the left pulmonary 

 artery to the left anterior pulmonary plexus, and along the 

 pulmonary artery to the anterior coronary plexus. [693] 



Deep Cardiac Plexus. This is much larger, lies on the sides 

 of the trachea, just above its bifurcation, and consists of two 

 connected lateral parts. The right half receives all the cardiac 

 branches of the right vagus, right inferior laryngeal, and right 

 superior, middle, and inferior cervical sympathetic ganglia. It 

 forms chiefly the anterior or right coronary plexus, which pro- 

 ceeds on the right coronary artery to the heart and receives 

 fibres from the superficial cardiac plexus. It sends branches 

 to the posterior coronary plexus, and the right anterior pulmon- 

 ary plexus. The left half receives the left superior cervical 

 cardiac, cardiac branches of the left inferior laryngeal nerve 

 and the left middle and inferior cervical sympathetic ganglia, 

 and a branch of the superficial cardiac plexus. It forms the 

 left or posterior coronary plexus, which proceeds on the left 

 coronary artery, receiving branches from the right half. It 

 also sends branches along the left pulmonary artery to the 

 left anterior pulmonary plexus. [694] 



Pulmonary Plexuses. The posterior, placed behind the root 

 of the lung, is formed by most of the vagus, with branches of 

 the second, third, and fourth thoracic sympathetic ganglia. 

 Numerous fine branches run on the bronchi and vessels to 

 the lung. The anterior lies on the front of the root of the lung 

 on each side and is formed by a few fibres from the vagus, with 

 others from the corresponding part of the deep cardiac plexus 

 and (left side) the superficial cardiac plexus. It supplies the 

 root of the lung in front. [694] 



[120] 



