468 VEINS. 



The Deep Palmar Veins accompany the deep palmar arch, being formed by 

 branches which accompany the ramifications of this vessel. They communicate 

 with the superficial palmar veins at the inner side of the hand ; and, on the outer 

 side, terminate in the venas comites of the radial artery. At the wrist, they receive 

 a dorsal and a palmar branch from the thumb, and unite with the deep radial 

 veins. Accompanying the radial artery, these vessels terminate in the vense 

 comites of the brachial artery. 



The Brachial Veins are placed one on each side of the brachial artery, receiving 

 branches corresponding with those given off from this vessel ; at the lower margin 

 of the axilla they unite with the basilic to form the axillary vein. 



The deep veins have numerous anastomoses, not only with each other, but also 

 with jhe superficial veins. 



The AXILLARY VEIN is of large size and formed by the continuation upwards 

 of the basilic vein. It commences at the lower part of the axillary space, and 

 increasing in size as it ascends, by receiving branches corresponding with those of 

 the axillary artery, terminates immediately beneath the clavicle at the outer mar- 

 gin of the first rib, and becomes the subclavian vein. This vessel is covered in 

 front by the Pectoral muscles and costo-coracoid membrane, and lies on the thoracic 

 side of the axillary artery. Opposite the Subscapularis, it is joined by a large 

 vein, formed by the junction of the vence comites of the brachial ; and near its 

 termination it receives the cephalic vein. This vein is provided with a pair of 

 valves opposite the lower border of the Subscapularis muscle ; valves are also 

 found, at the termination of the cephalic and subscapular veins. 



The SUBCLAVIAN VEIN, the continuation of the axillary, extends from the outer 

 margin of the first rib to the inner end of the sterno-clavicular articulation, where 

 it unites with the internal jugular, to form the vena innominata. It is in relation, 

 in front, with the clavicle and Subclavius muscle ; behind, with the subclavian 

 artery, from which it is separated internally by the Scalenus anticus and phrenic 

 nerve. Below, it rests in a depression on the first rib and upon the pleura. 

 Above, it is covered by the cervical fascia and integument. 



The subclavian vein occasionally rises in the neck to a level with the third part 

 of the subclavian artery, and, in two instances, has been seen passing with the 

 latter behind the Scalenus anticus. This vessel is provided with valves about an 

 inch from its termination in the innominate, just external to the entrance of the 

 external jugular vein. 



Branches. It receives the external and anterior jugular veins and a small branch 

 from the cephalic, outside the Scalenus ; and on the inner side of this muscle, the 

 internal jugular veins. 



The VENJE INNOMINATE (fig. 241) are two large trunks, placed one on each 

 side of the root of the neck, and formed by the union of the internal jugular and 

 subclavian veins of the corresponding side. 



The Right Vena Innominata is a short vessel, about an inch and a half in length, 

 which commences at the inner end of the clavicle, and, passing almost vertically 

 downwards, joins with the left vena innominata just below the cartilage of the first 

 rib, to form the superior vena cava. It lies superficial and external to the arteria 

 innominata ; on its right side the pleura is interposed between it and the apex of 

 the lung. This vein, at its angle of junction with the subclavian, receives the 

 right vertebral vein, and right lymphatic duct ; and, lower down, the right internal 

 mammary, right inferior thyroid, and right superior intercostal veins. 



The Left Vena Innominata, about three inches in length, and larger than the 

 right, passes obliquely from right to left across the upper and front part of the 

 chest, to unite with its fellow of the opposite side, forming the superior vena cava. 

 It is in relation, in front, with the sternal end of the left clavicle, the left sterno- 

 clavicular articulation, and with the first piece of the sternum, from which it is 

 separated by the Sterno-hyoid and Sterno-thyroid. muscles, the thymus gland or 

 its remains, and some loose areolar tissue. Behind, it lies across the roots of the 



