Anatomy of cardiovascular system

1. Development of venous
System
Dr. Mohammed Mahmoud Mosaed

2. Development of venous System
• In the fifth week, three pairs of major veins can
be distinguished:
• (a) Thevitelline veins (omphalomesenteric
veins), carrying blood from the yolk sac to the
sinus venosus.
• (b) The umbilical veins, originating in the
chorionic villi and carrying oxygenated blood to
the embryo.
• (c) The cardinal veins, draining the body of
the embryo proper.

5. Vitelline Veins
• There are 2 vitelline veins right and left
• Each one divided into distal, middle and
proximal parts by the developing liver
• The distal parts of 2 veins anastomosis around
the duodenum to form the portal vein
• The middle part of 2 veins forming the liver
sinusoids
• The proximal part of the left vein disappear
• The proximal part of the right above the liver
forming the hepatocardiac part of the inferior
vena cava

6. Umbilical Veins
• At first 2 umbilical veins are present (right and
left)
• The right vein completely disappears
• The proximal part of the left vein disappears
• The distal part of the left vein carries blood
from the placenta to the liver With the
increase of the placental circulation, a direct
communication forms between the left
umbilical vein and the inferior vena cava
through the ductus venosus.

9. Cardinal Veins
• The cardinal veins form the main venous drainage
system of the embryo.
This system consists of:
• The anterior cardinal veins, which drain the
cephalic part of the embryo,
• The posterior cardinal veins, which drain the rest
of the embryo.
• The short common cardinal veins; the anterior
and posterior veins join before entering the sinus
horn and form the short common cardinal veins.

10. • During the fifth to the seventh week, a number
of additional veins are formed:
• (a) the subcardinal veins, which mainly drain
the kidneys;
• (b) the sacrocardinal veins, which drain the
lower extremities; and
• (c) the supracardinal veins, which drain the
body wall by way of the intercostal veins, taking
over the functions of the posterior cardinal
veins.

11. Anterior cardinal veins
• There are 2 anterior cardinal veins (right and left ) and
anastomosis in between
• The left one disappears except its terminal portion
which retained as a small vessel, the left superior
intercostal vein
• The anastomosis forming the left brachiocephalic
vein
• The proximal part of the right cardinal vein with the
common cardinal vein forming the superior vena
cava
• The distal part of the right cardinal vein forming the
right brachiocephalic vein

14. posterior cardinal veins and the
supracardinal veins
• There are 2 posterior cardinal veins, with the
development the greater part of posterior
cardinal veins disappear in both sides and the
supracardinal veins take their places
• The right supracardinal vein with a small
portion of the right posterior cardinal vein
forming the azygos vein
• The left supracardinal vein forms the
hemiazygos veins which draines in the
azygos vein

16. subcardinal veins
• There are 2 subcardinal veins and
anastomosis in between
• the left subcardinal vein disappears, and only
its distal portion remains as the left gonadal
vein
• The anastomosis between the subcardinal
veins forms the left renal vein.
• the right subcardinal vein develops into the
renal segment of the inferior vena cava and
a small distal portion forms the right gonadal
vein which drain into the inferior vena cava

17. The sacrocardinal veins
• The anastomosis between the sacrocardinal
veins forms the left common iliac vein.
• The right sacrocardinal vein becomes the
sacrocardinal segment of the inferior
vena cava.
• When the renal segment of the inferior vena
cava connects with the hepatic segment,
which is derived from the right vitelline vein,
• The inferior vena cava, consisting of
hepatic, renal, and sacrocardinal
segments, is complete.