856 THE VASCULAR SYSTEM. 
terminates in the internal saphenous vein about the lower part of Scarpa’s triangle ; the 
other, the internal, receives a communication from the external saphenous vein, and 
ascends from the back of the thigh along its inner side to terminate in the long saphenous 
vein almost opposite the termination of the external superficial femoral vein. The last 
tributaries to enter the long saphenous vein are the superficial circumflex iliac, epigastric, 
and pudic veins. They accompany the corresponding arteries, and terminate in the long 
; saphenous vein immediately before the latter 
vessel perforates the cribriform fascia. 
The superficial circumflex iliac vein receives 
blood from the lower and outer part of the 
abdominal wall and the upper and outer part of 
the thigh. The superficial epigastric vein drains 
the lower and inner part of the abdominal wall, 
and the superficial pudic vein receives blood 
from the dorsum of the penis and the scrotum 
in the male, and from the labium majus in the 
Short female. 
saphenous 
vein 
The external or short saphenous vein 
(v. saphena parva) 1s formed by the union 
of the outer extremity of the dorsal 
venous arch with the outer dorsal digital 
vein of the little toe. At first it passes 
backwards along the outer side of the foot 
and below the external malleolus, lying on 
the external annular heament in company 
with the external saphenous nerve; then it 
ascends behind the external malleolus, and 
along the outer border of the tendo Achillis, 
still in company with the external saphenous 
nerve, to the middle of the calf, above which 
it is continued in the superficial fascia, accom- 
panied by the superficial sural artery, to the 
lower part of the popliteal space, where it 
pierces the deep fascia, and terminates in 
the popliteal vein. It communicates round 
the inner side of the leg with the internal 
| saphenous vein, and through the deep fascia 
eo With the deep veins, and it contains from six 
ech to twelve bicuspid valves. 
Tributaries.—It receives tributaries from 
the outer side of the foot, from the outer side 
and back of the heel, from the back of the leg, 
and occasionally a descending tributary from 
Fic. 590.—THE EXTERNAL OR SHORT SAPHENOUS the back of the thigh. Just before it pierces 
VEIN AND ITs TRIBUTARIES. the popliteal fascia it gives off a small branch 
which ascends round the inner side of the thigh 
and unites with the internal superficial femoral vein. In this way a communication is 
established between the external and internal saphenous veins; this communication is 
frequently enlarged, and not uncommonly constitutes the main continuation of the 
external saphenous vein. 
THE PORTAL SYSTEM. 
The portal system includes the veins which convey blood from almost the 
whole of the abdominal and pelvic parts of the alimentary canal, and from the 
spleen and pancreas, to the liver. The tributaries of origin of these veins agree 
closely with the terminal branches of the corresponding arteries. They are single 
vessels, which for some distance accompany the corresponding arteries, and are 
similarly named. The larger or terminal veins, however, leave their associated 
arteries; the inferior mesenteric vein joims the splenic vein, and the latter unites 
