fHE VESSELS. 345 



pelvis it is situated on the inside (and behind) in the femoral ring : on the inner 

 side (crural hernia passes down before it) ; below the mouth of v. saphena: 

 behind ; and at the inferior part of the thigh : on the outer side of the artery ; 

 in the popliteal region ; behind, and rather outside the art . poplittza. In the 

 foot and leg the deep veins are double for each artery, but they take a similar 

 course. The v. iliaca externa, only, does not possess valves. 

 Cutaneous veins (with very thick walls) : 



a. Saphena interna s. magna, arises from plexus dorsalis pedis, on the in- 

 ternal border of the foot, passes upon the dorsal surface of os metatarsi 



' L, and over the tarsus, curves from below upwards before the inner 

 malleolus, then ascends on the internal surface to the posterior border 

 of the tibia as far as behind condyl. intern, femor. (on the inner side of 

 the tendons of mm. semitendin., gracilis, and sartorius), inclines to the 

 front, and ascends along the anterior border of m. sartorius to the inner 

 and anterior surface of the thigh, perforates ihefasc. cruralis, and sinks 

 one inch below the femoral arch into the-?;, femoralis. It receives the 

 cutaneous veins of the thigh, of the anterior abdominal walls and Vv. 

 pudend. externce, and branches of the deep veins. 



b. Saphena externa s. parva arises from plexus dorsalis pedis, on the outer 

 border of the foot, passes round behind the external malleolus, at first 

 on the outer border of the tendo Achillis, then over this to the centre of 

 the fibula, and thus to the popliteal region, where it sinks, between 

 nerv. tibialis andfibularis, close to v. articular infer, interna. into the 

 popliteal vein. It covers and crosses the n. peronceus twice. It receives 

 branches from the sole of the foot and leg, unites with v. saphena interna 

 at the malleolus and back of the foot ; and sometimes also opens into 

 it. 



598. II. Vena ported s. portarum, the portal vein, 



forms a tolerably independent system of vessels, the roots of which 

 pass forth from the capillary rete of the organs of digestion, unite 

 into one venous trunk, which again ramifies, in a dendritic man- 

 ner, like an artery^, in the liver, so that its blood passes along 

 through the vv. hepatica, again into the circulation. It corre- 

 sponds to Artt. cceliaca, mesenterica superior and inferior, with 

 the exception of art. hepatica. Origin : from the vv. mesenterica 

 superior and linealis, united at an acute angle, behind the head of 

 the Pancreas, the duodenum, in the centre before the vertebral 

 column, to the left of the Vena cava inferior. Course : from be- 

 low upwards, and from left to right, four inches long, to the left 

 extremity of the transverse fossa of the liver, in which it bifurcates. 

 Situation : behind cap. pancreatis and pars descend, duodeni, art. 

 and ductus hepaticus, before v. cava. infer. ; within the capsula 

 Glissonii, between the two layers of Kg. hepatico-duodenale. 



