THE HEART AND VASCULAR SYSTEM. 213 



3. Utero-nif/hiaf plr.ruscs. These correspond in the female 

 with the prostatic, and communicate with the vesical and haemor- 

 rhoidal plexuses, the ovarian, pudic, and through the uterine 

 veins join the internal iliac veins. 



During pregnancy these veins or plexuses become greatly dis- 

 tended and enlarged, forming the uterine sinuses, but retain a 

 straight course. 



The pudic vein follows the same course as the artery, com- 

 municates with the prostatic and haemorrhoidal plexuses, and 

 terminates in the internal iliac vein. 



In the female it originates from the clitoris and perineum, 

 and communicates with the vaginal plexus. 



The dorsal vein of the penis returns the blood from the body 

 of that organ. It commences as two venae comites of the dorsal 

 artery, which unite on the dorsal surface of the root of the penis, 

 perforates the triangular ligament, and again divides to termi- 

 nate in the prostatic plexus. 



The veins of the corpus cnrrrnosum emerge at the lower 

 groove, and turn round their outer side to join the dorsal vein. 



The dorsal vein of the clitoris has a corresponding origin and 

 course, and empties into the vaginal plexus. 



The EXTERNAL ILIAC VEIN, the continuation of the femoral, 

 lies internal to the artery beneath Poupart's ligament, and joins 

 II ic internal iliac opposite the sacro-iliac symphysis, to form the 

 common iliac vein. It runs along the brim of the pelvis. It 

 receives at its commencement the vena3 comites of the epigastric 

 artery and the circumflex iliac. 



LOWEB KxTKKMiTY. The deep veins of the lower extremity 

 pursue the exact course of the corresponding arteries, anastomos- 

 ing across the vessels they accompany, except the femoral, which 

 has but one vein. 



The popliteal vein, formed by the junction of the anterior 

 and posterior tibial veins, ascends to the low r er margin of 

 Hunter's canal, where it becomes the femoral. It receives the 

 articular veins, siiral veins, and the external saphenous. At its 

 commencement it lies internal and superficial, at the middle of 

 the space directly behind, and, in the upper part of its course, 

 external to the artery. 



The femoral vein, at first behind the artery, inclines to the 

 inner side as it ascends, and at Ton part's ligament becomes the 

 external iliac. It receives the profunda femoris, the internal 

 saphenous vein, and numerous muscular veins. 



The superficial veins of the lower extremity consist of two 

 principal trunks: the external short sap/tenons, or vein, com- 

 mences on the dorsum of the foot, passes behind the outer mal- 



