844 THE VASCULAR SYSTEM. 
numerous transverse anastomoses which cross in front of or behind the artery. . 
The axillary vein, however, requires more detailed consideration. 
THE AXILLARY VEIN. 
The axillary vein (v. axillaris, Fig. 561) commences, as the direct continuation 
of the basilic vein, opposite the lower border of the teres major. It passes upwards 
and inwards through the axilla, along’ the inner side of the corresponding artery, 
© 
and terminates at 
the outer border 
of the first rib 
by becoming the 
subclavian vein. 
It possesses a 
bicuspid valve 
Radial veins which is usually 
situated opposite 
the lower border 
of the subscapu- 
laris muscle. 
Relations. — 
Its anterior rela- 
____Commencement tions are similar 
of median vein to’ thosewonethe 
axillary artery, 
but, in addition, 
the vein is crossed 
in front, under 
cover of the clavi- 
cular part of the 
pectoralis major, 
by the pectoral 
branches of the 
acromio - thoracic 
— Dorsal digital veins artery, and by 
branches of the 
internal anterior 
thoracic nerve, 
and it receives in 
front, just above 
the upper border 
of the pectoralis 
minor, the ter- 
mination of the 
cephalic vein. 
Behind it are 
the muscles which 
form the posterior 
wall of the axilla, 
the axillary fat, and the first serration of the serratus magnus. The long thoracic nerve 
intervenes between it and the serratus magnus, and the subscapular nerves and the sub- 
scapular artery pass between it and the subscapularis. 
It is separated from the axillary artery on the outer side, in the lower part of its extent 
by the ulnar and internal cutaneous nerves, in the middle of its course by the inner cord 
of the brachial plexus, and in the upper part of the axilla, behind the costo-coracoid 
membrane, by the internal anterior thoracic nerve. To its inner side lie the outer set of 
axillary glands, and in the lower part of the axilla the lesser internal cutaneous nerve. 
Tributaries.—In addition to tributaries corresponding with the branches of the 
axillary artery, it receives the venz comites of the brachial artery, at the lower borderiof 
the subscapularis, and the cephalic vein, which joins it at the upper border of the small 
pectoral muscle. 
Posterior ulnar 
vein 
Commencement 
of posterior ulnar 
vein 
Dorsal venous 
Dorsal 
digital — 
veins 
Fic. 584.—SuPERFICIAL VEINS ON THE DORSUM OF THE HAND AND DicitTs. 
| 
| 
