TJwracic Aneurysm 



185 



front of the chest and in the epigastric region. The peripheral pains 

 due to aneurysm are most likely on one side, whilst those due to spinal 

 caries are usually bilateral and symmetrical. Further, the aneurysm 

 of the thoracic aorta may appear as a pulsating tumour by the costal 

 angles. If it bulge forwards it presses upon the oesophagus, causing 

 dysphagia, or upon the lung, giving rise to shortness of breath, and to 

 the presence of a dull percussion-note. If it compress the thoracic 

 duct rapid wasting occurs. Pushing the heart forwards, it causes pal- 

 pitation and faintness, and an embarrassed circulation. 



V 



I, Aorta; n, pulmonary artery ; d' d', anterior jugular veins ; cc', internal jugulars; dd, ex- 

 ternal jugulars ; a a', innominate veins ; in, superior cava ; <?, great azygos ; IV, hepatics. 

 N.B. All the veins are anterior to the arteries. (A. THOMSON.) 



It may at last leak through an ulcerated patch upon the skin, or 

 may discharge itself into the oesophagus, pleura, or pericardium, or into 

 a bronchus ; or its contents may be extravasated along the posterior 

 mediastinum. 



The branches of the thoracic aorta are bronchial, pericardial, 

 cesophageal, intercostal, and posterior mediastinal. 



The intercostal arteries are nine on each side, the first and second 

 spaces being supplied by the superior intercostal of the subclavian 



