676 ANGIOLOGY 



The deep dorsal vein of the penis communicates with the internal pudendal veins, 

 but ends mainly in the pudendal plexus. 



4. The Obturator Vein (v. obturatoria) begins in the upper portion of the adductor 

 region of the thigh and enters the pelvis through the upper part of the obturator 

 foramen. It runs backward and upward on the lateral wall of the pelvis below the 

 obturator artery, and then passes between the ureter and the hypogastric artery, 

 to end in the hypogastric vein. 



5. The Lateral Sacral Veins (w. sacrales laterales) accompany the lateral sacral 

 arteries on the anterior surface of the sacrum and end in the hypogastric vein. 



6. The Middle Hemorrhoidal Vein (v. hcemorrhoidalis media) takes origin in the 

 hemorrhoidal plexus and receives tributaries from the bladder, prostate, and 

 seminal vesicle; it runs laterahvard on the pelvic surface of the Levator ani to 

 end in the hypogastric vein. 



The hemorrhoidal plexus (plexus hcemorrhoidalis) surrounds the rectum, and 

 communicates in front with the vesical plexus in the male, and the uterovaginal 

 plexus in the female. It consists of two parts, an internal in the submucosa, and an 

 external outside the muscular coat. The internal plexus presents a series of dilated 

 pouches which are arranged in a circle around the tube, immediately above the 

 anal orifice, and are connected by transverse branches. 



The lower part of the external plexus is drained by the inferior hemorrhoidal 

 veins into the internal pudendal vein; the middle part by the middle hemorrhoidal 

 vein which joins the hypogastric vein; and the upper part by the superior hemor- 

 rhoidal vein which forms the commencement of the inferior mesenteric vein, 

 a tributary of the portal vein. A free communication between the portal and sys- 

 temic venous systems is established through the hemorrhoidal plexus. 



The veins of the hemorrhoidal plexus are contained in very loose, connective 

 tissue, so that they get less support from surrounding structures than most other 

 veins, and are less capable of resisting increased blood-pressure. 



The pudendal plexus (plexus pudendalis; vesicoprostatic plexus) lies behind the 

 arcuate pubic ligament and the lower part of the symphysis pubis, and in front of 

 the bladder and prostate. Its chief tributary is the deep dorsal vein of the penis, 

 but it also receives branches from the front of the bladder and prostate. It com- 

 municates with the vesical plexus and with the internal pudendal vein and drains 

 into the vesical and hypogastric veins. The prostatic veins form a well-marked 

 prostatic plexus which lies partly in the fascial sheath of the prostate and partly 

 between the sheath and the prostatic capsule. It communicates with the pudendal 

 and vesical plexuses. 



The vesical plexus (plexus vesicalis) envelops the lower part of the bladder and 

 the base of the prostate and communicates with the pudendal and prostatic plexuses. 

 It is drained, by means of several vesical veins, into the hypogastric veins. 



The Dorsal Veins of the Penis (vv. dorsales penis') are two in number, a superficial 

 and a deep. The superficial vein drains the prepuce and skin of the penis, and, 

 running backward in the subcutaneous tissue, inclines to the right or left, and opens 

 into the corresponding superficial external pudendal vein, a tributary of the great 

 saphenous vein. The deep vein lies beneath the deep fascia of the penis; it receives 

 the blood from the glans penis and corpora cavernosa penis and courses backward 

 in the middle line between the dorsal arteries; near the root of the penis it passes 

 between the two parts of the suspensory ligament and then through an aperture 

 between the arcuate pubic ligament and the transverse ligament of the pelvis, 

 and divides into two branches, which enter the pudendal plexus. The deep vein 

 also communicates below the symphysis pubis with the internal pudendal vein. 



The uterine plexuses lie along the sides and superior angles of the uterus between 

 the two layers of the broad ligament, and communicate with the ovarian and 

 vaginal plexuses. They are drained by a pair of uterine veins on either side: these 





