The Aorta. 



387 



A. subolavia 

 dextra 



A. carotis communis dextra 



A. subclavia sinistra 



A. carotis communis sinistra 



Aorta aseendens 



Bulbus aortae 



A. coronaria [cordis] dextra 



Isthmus aortae 



Aortic spindle 



Aorta 

 thoracal is 



A. coronaria 

 [cordis] sinistra 



"^^^ 



Sinus aortae [Valsalvae] 



433. Aortic arch with its branches, 



viewed from the left and in front. 



(Aftm- a plaster mould.) 



The parietal layer of the pericardium (see Kgs. 432, 626 631) is fused, on its lower 

 surface, firmly with the diaphragm, on the posterior surface loosely with the oesophagus and 

 the aorta thoracahs ; to the right and left it is intimately united with the pleura pericardiaca. 

 In front it is partly covered by the thymus and loosely connected with it; it lies in part just 

 behind the corpus sterni and is fastened to it by several powerful, tendinous bands of fibers, 

 the ligameiita sternopericardiaca (not illustrated), as well as by loose connective tissue. 



The aorta runs, from the ostium arteriosum sinistrum, at first, upward (aorta aseendens) ; 

 it then bends around backward (arcus aortae), and goes finally downward, above, in front of 

 the thoracic spme (aorta thoracalis), below, in front of the lumbar spine (aorta abdominalis) . 

 It ends in front of the 4tii lumbar vertebra, a Kttle below the navel. 



The beginning of the aorta aseendens (see also Figs. 410, 411, 427 and 42S) lies 

 behind that of the a. puhnonalis and presents a flask-like swelling (bulbus aortae) with three 

 smaller bulgings (sinus aortae [Valsalvae]), of which each corresponds to one valvula semi- 

 lunaris aortae. Thence the aorta passes upward and turns only a little to the right and 

 forward; it lies behind the right auricle of the heart and behind the corpus sterni, on the 

 right side of the a. puhnonalis and on the left side of the v. cava superior; behind, it adjoins 

 the left atrium and the ramus dexter a. pulmonalis. The only larger branches given off by it 

 are the two aa. coronariae [cordis] (see also Figs. 428 and 429). 



