Pelvic veins

The common iliac vein (v. iliaca communis) is a large valveless vessel. It is formed at the level of the sacroiliac joint by the confluence of the internal and external iliac veins. The right common iliac vein passes first behind and then laterally to the artery of the same name. The left common iliac vein is located medial to the artery of the same name. The median sacral vein (v. sacralis mediana) flows into it.

At the level of the intervertebral disc, between the IV and V lumbar vertebrae, the right and left common iliac veins merge, forming the inferior vena cava.

The internal iliac vein (v. iliaca interna) rarely has valves and lies on the lateral wall of the small pelvis behind the artery of the same name. The areas from which its tributaries bring blood correspond (with the exception of the umbilical vein) to the branches of the artery of the same name. The internal iliac vein has parietal and visceral tributaries, and the latter, with the exception of the veins of the urinary bladder, do not have valves. As a rule, they begin from the venous plexuses surrounding the organs of the small pelvis.

Parietal tributaries:

1. superior and inferior gluteal veins (vv. gluteales superiores et inferiores);
2. obturator veins (vv. obturatoriae);
3. lateral sacral veins (vv. sacrales laterales) are paired;
4. iliolumbar vein (v. iliolumbalis) is unpaired. These veins are adjacent to the arteries of the same name and have valves.

Visceral tributaries:

1. the sacral plexus (plexus venosus sacralis) is formed by anastomoses of the roots of the sacral lateral and median veins;
2. prostatic venous plexus (plexus venosus prostaticus) in men. This is a venous plexus of large veins surrounding the prostate gland and seminal vesicles, into which the deep dorsal vein of the penis (v. dorsalis profunda penis), the deep veins of the penis (vv. profundae penis) and the posterior scrotal veins (vv. scrotales posteriores), penetrating into the pelvic cavity through the urogenital diaphragm, flow;
3. vaginal venous plexus (plexus venosus vaginalis) in women. This plexus surrounds the urethra and vagina. At the top it passes into the uterine venous plexus (plexus venosus utennus), surrounding the cervix. Blood flows out of these plexuses through the uterine veins (vv. uterinae);
4. The vesical venous plexus (plexus venosus vesicilis) surrounds the bladder from the sides and in the fundus. Blood from this plexus flows through the vesical veins (vv. vesicales);
5. The rectal venous plexus (plexus venosus rectalis) is adjacent to the rectum from behind and from the sides. This plexus is located in its submucosa and is most complexly developed in the lower part of the rectum. From this plexus, blood flows out through one unpaired and two paired middle and inferior rectal veins, anastomosing with each other in the walls of the rectum. The superior rectal vein (v. rectalis superior) flows into the inferior mesenteric vein.

The middle rectal veins (vv. rectales mediae) are paired and collect blood from the middle section of the organ (flow into the internal iliac vein). The lower rectal veins (vv. rectales inferiores) are also paired and drain blood into the internal pudendal vein (v. pudenda interna), a tributary of the internal iliac vein.

The veins of the human body are connected to each other by numerous anastomoses. Of greatest practical importance are intersystemic venous anastomoses, i.e. by means of which the systems of the superior and inferior vena cava and portal veins are connected to each other.

The external iliac vein (v. iliaca externa) is a continuation of the femoral vein (the border between them is the inguinal ligament), receives blood from all the veins of the lower limb. This vein has no valves, runs upward next to the artery of the same name and is adjacent to the lumbar major muscle on the medial side. At the level of the sacroiliac joint, it joins the internal iliac vein, forming the common iliac vein. Immediately above the inguinal ligament (almost within the vascular lacuna), the inferior epigastric vein (v. epigastrica inferior) and the deep vein that encircles the ilium (v. circumflexa iliaca profunda) flow into the external iliac vein. The position and tributaries of these veins correspond to the branches of the arteries of the same name. The inferior epigastric vein anastomoses with the iliolumbar vein, a tributary of the internal iliac vein.