710 



THE VASCULAR SYSTEMS 



Applied Anatomy. Thrombosis of larger or smaller tributaries of the pulmonary veins 

 is common in inflamed areas of the lung; or as a consequence of pressure from tumors, but it 

 does not give rise to any special symptoms. 



: CORONARy 

 LEFT: LEFT 



VENTRICLE AURICLE 



ENTRANCE OF 

 VENA AZYGOS 

 BRANCH OF PUL- 

 MONARY ARTERY 



FIG. 493. Pulmonary veins, seen in a dorsal view of the heart and lungs. The left lung is pulled to the 

 left, and the right lung has been partly cut away to show the ramifications of the air tubes and bloodvessels. 

 (Testut.) 



THE SYSTEMIC VEINS. 



The systemic veins may be arranged into three groups: (1) The cardiac veins, 

 which open directly into the right auricle of the heart. (2) Those of the head 

 and neck, upper extremity, and thorax, which terminate in the superior vena cava. 

 (3) Those of the lower extremity, abdomen, and pelvis, which terminate in the 

 inferior vena cava. 



THE CARDIAC VEINS. 



The coronary sinus (sinus coronarius) is a wide venous channel about an 

 inch in length which receives the majority of the veins draining the blood from 

 the substance of the heart. It is situated in the posterior part of the auriculo- 

 ventricular groove, and is covered by muscle fibres from the left auricle. It 

 terminates in the right auricle between the opening of the inferior vena cava and 

 the auriculoventricular aperture, its orifice being guarded by a semilunar valve, 

 the coronary valve, or valve of Thebesius. 



Tributaries. 



Great cardiac or left coronary. Middle cardiac. 



Small cardiac or right coronary. Posterior vein of the left ventricle. 



Oblique vein of Marshall. 



