696 BLOOD-VASCULAR SYSTEM OF THE HORSE 
otherwise to the artery. The external pudic vein (V. pudenda externa) arises 
chiefly from a rich plexus of large veins situated above and along the sides of the 
penis and prepuce in the male, the mammary glands in the female. It passes 
through a foramen in the anterior part of the tendon of origin of the gracilis and 
runs outward behind the pectineus to unite with the deep femoral vein. The right 
and left veins are connected by a large transverse anastomotic branch which lies 
in the subpubic groove, and each has a large connection with the obturator vein. 
Each receives the posterior abdominal vein (V. abdominalis caudalis), which ac- 
companies the artery of like name. The subcutaneous abdominal vein (V. ab- 
dominalis subcutanea) arises in the skin and cutaneous muscle of the ventral 
abdominal wall, anastomoses with the internal and external thoracic and deep 
abdominal veins, and joins the external pudie or the posterior abdominal vein. 
A small vein may accompany the external pudic artery in the inguinal canal. 
2. The anterior femoral vein (V. femoris cranialis) accompanies the artery. 
3. The saphenous vein (V. saphena) (Figs. 575, 576, 583) arises on the dorso- 
medial surface of the tarsus as the upward continuation of the medial metatarsal 
vein. Its course is distinctly visible. It ascends on the subcutaneous surface of 
the tibia and the popliteus muscle, enclosed between layers of the deep fascia, in- 
clines a little backward to the proximal part of the leg, then deviates slightly for- 
ward, runs upward on the gracilis, passes between that muscle and the sartorius, 
and joins the femoral or the external pudic vein.!| On the upper part of the capsule 
of the hock joint it forms an arch with the anterior tibial vein. The vein has 
numerous valves. The satellite artery is relatively small, and lies in front of the 
vein as far as the Junction with the recurrent tibial vein, which it accompanies on 
the leg. It receives the recurrent tibial vein (V. recurrens tibialis) at the proximal 
fourth of the leg. This vessel arises at the distal third of the leg, where it forms an 
arch with the posterior tibial vein; here it is a satellite of the artery of like name. 
It ascends in the furrow in front of the gastrocnemius tendon, inclines forward at 
the proximal third of the leg, and joins the saphenous vein at an acute angle. It 
gives off a branch which ascends with the artery and joins the posterior femoral or 
the popliteal vein.?, A smaller vein from the anterior face of the metatarsus joins 
the saphenous at the hock. 
4. Muscular branches which correspond to the arteries. 
5. The posterior femoral vein (V. femoris caudalis) is a satellite of the artery. 
It receives the recurrent tarsal vein (V. tarsea recurrens), which arises at the lateral 
side of the hock, ascends on the deep fascia of the lateral surface of the leg in front 
of the tendo Achillis, passes between the biceps femoris and semitendinosus, and 
joins the posterior femoral vein. It is connected with the recurrent tibial vein by 
a large anastomotic branch which crosses in front of the tuber calcis. Usually a 
branch from it ascends along the great sciatic nerve and anastomoses with the ob- 
turator vein. 
The popliteal vein (V. poplitea) lies along the medial side of the artery (Fig. 
584). It is formed by the confluence of anterior and posterior tibial veins. 
Two anterior tibial veins (Vy. tibiales anteriores) usually accompany the artery 
of like name; the lateral vein is much the larger.? In other cases there is a single 
F 1 The place and mode of termination are quite variable. It may disappear from the surface 
of the thigh at any point above the distal third. In some cases it passes through the anterior 
part of the gracilis instead of dipping in between that muscle and the sartorius, and more rarely 
it joms the external pudic vein at the origin of the gracilis. 
2 The arrangement here is subject to variation. Some authors regard the ascending branch 
of this description as the trunk, and the connection with the saphenous as an anastomotic branch. 
The latter is usually, so far as size is concerned, the trunk. 
3 The large size of this vein, the thinness of its wall, and the fact that it is separated only by a 
thin layer of muscle (lateral part of tibialis anterior) from the deep peroneal nerve should be noted 
with reference to section of that nerve. The vein is sometimes markedly varicose in the proximal 
part of the leg. 
