244 ANATOMY OF THE DOMESTIC FOWL 



The blood from the neural canal, including the spinal cord, is 

 collected in one long vein extending from the head to the tail on 

 the upper side of the cord. This vein has sinus-like expansions. 

 Between each two vertebra it anastomoses with the vertebral vein 

 on each side. In the lumbo-sacral region these anastomotic branches 

 empty into the hypogastric veins. 



The vena intercostalis is formed in the costal region and anas- 

 tomoses with the vein extending longitudinally between the 

 capitulum and the tuberculum of the rib. 



The vena vertebralis posterior at the height of the first and the 

 second dorsal vertebrae, empties into the main trimk of the verte- 

 bral vein. Its lower roots come out near the side of the kidney, 

 and imite, forming a large ascending trunk uniting with the vena 

 vertebralis anterior forming one large trunk, which extends into the 

 chest cavity. 



The posterior vertebral vein also receives a large vein from the skin 

 of the outer tarsal region and a few vessels from the muscles of 

 the outer abdominal and the outer costal region, from the skin, 

 from the pectoralis muscles, and from -the shoulder region. 



VEINS OF THE THORAX 



Branches of the Vena Stjbclavia 



The vena thoracica externa (Fig. 73, No. 2) is made up of veins 

 mainly from the pectoral group of muscles. The posterior branch 

 anastomoses with the vena cutinea. Its anterior branch is made up 

 mainly of branches from the furcular region. It empties into the 

 vena pectoraHs externa and the vena pectoralis externa empties into 

 the vena subclavia. 



The vena coracoidea comes out of the region of the shoulder- 

 joint, passes downward along the inner surface of the coracoid, 

 and receives small branches from the walls of the arteria brachia 

 cephalica and from the pericardium. 



The vena stemalis (Fig. 73, No. i) is made up of two branches. 

 The outer branch comes from the muscles of the subclavian region 

 passes over the cristi stemi, medially, to the sterno-coracoid joint 

 and into the breast cavity, where it receives the inner branch, 

 which drains the inner surface of the breast-bone. 



The vena thoracica interna empties into the vena cava anterior. 

 It extends from the abdominal muscles where it communicates with 



