THE THORAX 



327 



then continues backwards between the arch of the aorta 

 and the base of the heart. It passes dorsal to the pulmonary 

 vessels and the bronchus (where it gives off pulmonary 

 branches) to continue along the ventrolateral wall of the 

 oesophagus. The recurrent nerve passes forward dorsal 

 to the arterial ligament and over the dorsal side of the 

 aortic arch to proceed craniad along the lateral surface of 

 the trachea. 



Near its beginning, the recurrent branch gives off 

 efferent rami to the cardiac plexus (plexus cardiacus), a 

 network of autonomic nerve fibres lying between the aortic 

 arch and the pulmonary artery and distributed to the heart 

 (coronary plexus) and the immediately adjacent arteries. 



{d) The ramus cardiacus of the vagus has already been observed 

 running along the dorsal 

 surface of the common 

 carotid artery (p. 302). 

 In front of the subcla- 

 vian artery, this sensory 

 branch is at first close- 

 ly associated with the 

 vagus trunk, lying on its 

 medial side. On the 

 right side it passes to 

 the dorsal surface of the 

 subclavian, and on the 

 left to the dorsal surface 

 of the aortic arch. Its 

 posterior end connects 

 with the cardiac plexus 

 •through which its fibres 

 come from the walls of 

 the adjacent vessels and 



of the heart. ■ r^^- ^^^- ^^^^ of the venous and lymphatic 



^ trunks of the anterior portion of the body. 



/ \ -T*! I- • / After McClure and Silvester. 



(ej Ine phrenic nerve (n. a., azygos vein; ao, aorta; C.S., left superior 



I.N,. , , caval vein; d.th., thoracic duct; j.e., j.i., and 



pnreniCUS) is a stout j.tr., external, internal, and transverse jugular 



J . . I* n r veins; s., left subclavian vein; tr.s., transverse 



cord arismg chietly from scapular vein. 



