238 



Veins. 



Plexus spinal, int. 



587. The Sinuses of the Dura Mater. 



Lateral view. 



The venous blood is returned to the right auricle by two prin- 

 cipal trunks, the superior or descending and the inferior or 

 ascending Venae cavac. 



The superior Vena cava descends to the right auricle of the heart 

 at the right side of the ascending arch of the aorta and in front of 

 the right pulmonary vessels. It is formed by the union of the right and 

 left innominate veins .s. Venae anonymae and receives the V. azygos. 

 Ench V. mnominata is formed by the union of the subclavian, internal 

 (common) jugular and external jugular veins ; each is joined by the following 

 veins: the vertebral, internal mammary, superior inter- 

 costal, t h y m i c, p e r i c a r d i a c, s u p e r i o r p h r e n i c and anterior 

 mediastinal; the left also by the V. tliyrcoidca ima. 



The common jugular, V. jugular is communis, passes up as far 

 as the superior triangle of the neck on the outer side of the common 

 carotid, where it is formed by the union of the internal jugular 

 and common facial veins. 



