Introduction

The embryo's vein system develops out of a very irregular network of capillaries, from which finally individual ones transform themselves definitively into veins while others disappear again. The result of this is that the venous system is not very uniform, and in the adult far more variants of venous outflows than on the arterial side exist. One can nevertheless distinguish among three basic systems: cardinal, umbilical and omphalomesenteric. The pulmonary veins cannot be counted as belonging to these three systems and are treated separately.

The cardinal system

The cardinal veins form as the basis for the intraembryonic venous part of the circulatory system. Various venous systems appear in various stages of the embryogenesis and partially disappear again

Very early in the development two paired systems appear:

  • The superior cardinal veins bring the blood from the head region via the left and right common cardinal vein
  • The inferior cardinal veins drain the blood from the lower half of the body into the two common cardinal veins

From here, the blood is emptied into the sinus venosus and into the atrium via the sinus horns.

Fig. venensystem01 - Development of the cardinal vein system
media/module16/p6_kardinalvenen10.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem01

Very early in the development two paired intraembryonic systems appear:
the superior cardinal veins (vv. cardinales anteriores) bring the blood from the head region via the left and right common cardinal vein.
The inferior cardinal veins (vv. cardinales posteriores) drain the blood from the lower half of the body into the common cardinal vein. From here it empties via the sinus horns into the sinus venosus and into the atrium.
In addition, a further mesh of veins, the subcardinal vein, appears on both sides behind the nephrogenic cord with the formation of the urogenital system.

Fig. venensystem02 - Development of the cardinal vein system
media/module16/p6_kardinalvenen12a.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem02

Soon not only do anastomoses arise in the vertical direction on both sides of the aorta, but also between the left and right subcardinal vein. These anastomoses are found in front of the aorta dorsalis.

Fig. venensystem03 - Development of the cardinal vein system
media/module16/p6_kardinalvenen13.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem03

The right subcardinal vein obtains access to the vessels of the liver (v. revehentes) that have broadened on the right side to form a hepatocardiac canal.
With the begin of limb development a venous runoff from arm and leg anlagen is formed.

Fig. venensystem04 - Development of the cardinal vein system
media/module16/p6_kardinalvenen14a.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem04

Like the cardiac sinus venosus the entire venous system of the lower half of the body is also located towards the right. A further longitudinal system arises. It is called the supracardinal veins and has a close relationship with the truncus sympathicus.

Fig. venensystem05 - Development of the cardinal vein system
media/module16/p6_kardinalvenen15a.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem05

Now the inferior cardinal veins slowly atrophy on both sides. What remains is a vein plexus that gets larger and larger in the sacral area, the sacrocardinal plexus. The supracardinal vein is also involved. Now the movement of the venous runoff towards the rights is clearly visible.

Fig. venensystem06 - Development of the cardinal vein system
media/module16/p6_kardinalvenen16a.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem06

The inferior cardinal vein and the anastomosis to metanephros still exist only in the caudal part of the embryo. Further along, a connection between the right supracardinal vein and the right subcardinal vein arises.
The connection of the right subcardinal vein with the liver veins has extended.
Near the heart the left sinus horn as well as the left omphalo-mesenteric vein atrophy. Also in the upper area of the body the vein system is moved to the right. A brachiocephalic anastomosis forms between the left and right superior cardinal vein.

Fig. venensystem07 - Development of the cardinal vein system
media/module16/p6_kardinalvenen17b.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem07

The inferior cardinal veins now only exist near the heart and in the sacral region. Between them a prominent intersubcardinal anastomosis net has formed, out of which the kidney veins will be engendered among other things.
Also the supply for the two suprarenal glands as well as the gonad anlagen will arise from it.

Fig. venensystem08 - Development of the cardinal vein system
media/module16/p6_kardinalvenen18c.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem08

Here one can clearly see that the inferior vena cava is put together from several sections of various vein systems. In the abdominal region there are three sets of paired veins: the renal vein, the suprarenal vein and the testicular or ovarian vein. Nevertheless, the blood from the left gonadal vein (testicular/ovarian) does not flow into the v. cava but, due to its location on the right, but into the left renal vein.
In the sacral region a median sacral vein has formed from the sacral plexus. In further development, the pelvic veins also are formed from it.
An anastomosis forms below the liver between the two supracardinal veins out of which a part of the hemiazygos vein will arise.

Fig. venensystem09 - Development of the cardinal vein system
media/module16/p6_kardinalvenen21.gif

  1. Sinus venosus
  2. Liver
  3. Inferior cardinal vein
  4. Anastomosis (kidney development)
  5. Subcardinal vein
  6. Superior cardinal vein
  7. Intersubcardinal anastomosis
  8. Iliac vein
  9. Subclavian vein
  10. Supracardinal vein
  11. Sacral plexus
  12. Left brachiocephalic vein
  13. Suprarenal vein
  14. Gonadal vein (testicular/ovarian)
15
Median sacral vein
16
Common iliac vein
17
Renal vein
18
Accessory hemiazygos vein
19
Hemiazygos vein
20
Azygos vein
21
Right brachiocephalic vein

Inferior cardinal vein
(posterior)
Subcardinal vein
Supracardinal vein
Omphalomesenteric vein
Umbilical vein

Legend
Fig. venensystem09

At the end of the embryonic period the vein system has nearly reached the condition of an adult.
The right supra- and subcardinal vein as well as the liver veins, that form the liver-heart-canal, are involved in forming the inferior vena cava.
In the sacral region the common iliac vein as well as the internal and external iliac vein have formed out of the sacral plexus following diverse transformational processes.
It is to be said again that the gonad vein pair do not have their inlets at the same place.

The adult venous system is much more variable as the arterial system. Through transformative processes during the development the individual sections arise from various portions of the embryonic venous system.

Overview
Overview of the origin of the adult venous system.