Development of inf venacava and pulmonary veins

1. Development of Inf. venacava
and Pulmonary vein
AnupPandey
Dept. of Human Anatomy
B.P. KoiralaInstitute of Health Sciences
DharanNepal

2. Cardinal veins
•Anterior cardinal veins:
drains the cephalic part of
the embryo, including the
brain.
•Posterior cardinal veins:
drain the rest of the part of
the embryo.
At their cranial ends these
veins join the ant cardinal
veins to form the common
cardinal vein.

3. •Near their caudal end
they receive veins of the
lower limb bud –external
iliac veinand of the pelvis
–internal iliac veins.
•The caudal ends of the
two posterior cardinal
veins become
interconnected by a
transverse anastomosis.

4. •Subcardinalveins: formed
in relation to the
mesonephroswhich
communicate cranially and
caudally with the posterior
cardinal veins.
•The subcardinalsreceive
the veins from the
developing kidneys.

5. •At the level of the renal
veins the two subcardinal
veins become
interconnected by a
transverse inter-subcardinal
anastomosis.

6. •The cranial part of the rt
subcardinalveins also
establishes an anastomosis
with the right hepatocardiac
channel.

7. •Supracardinalveins
Communicate cranially and
caudally with the posterior
cardinal veins and also with
the subcardinalveins thrthe
subcardinal-supracardinal
anastomoses.

8. •Many parts of this
longitudinal venous
channels disappear
•The veins that remain give
rise to the inferior vena
cava, renal vein, veins of
gonads and the suprarenal
veins.

9. •Inferior venacava:
derived from:
1.Lowest part of the rt
posterior cardinal vein and
the anastomosisbetntwo
posterior cardinal veins.
2.Lowest part of the
rt.supracardinalvein
3.Rt. Supracardinal-
subcardinalanastomosis.
4.Right subcardinalvein
5.Subcardinal-hepatocardiac
anastomosis.
6.Rt. Hepatocardiacchannel.

10. •Rtcommon iliac vein:
derived from the most
caudal part of the rt.
posterior cardinal vein.
•Left common iliac vein:
from the anastomosisbet
n
two posterior cardinal veins.
•Rtrenal vein: derived from
mesonephricvein that
drains into the rt
subcardinalvein.

11. •Left renal vein:
derived from
a)Mesonephricvein
that drains into left
subcardinalvein
b)Small part of the left
subcardinalvein
c)Inter-subcardinal
anastomosis.

12. •Suprarenal vein: derived
from the remnants of the
parts of subcardinalveins
above the inter-subcardinal
anastomosis.

13. •The termination of the rt
suprarenal vein in the IVC
and that of the left
suprarenal vein in the left
renal veinis because of
their developmental origin.
•Gonadalveins: derived
from the remnants of the
parts of subcardinalveins
below the inter-subcardinal
anastomosis.

14. Clinical correlates
•Double inferior venacava:
generally the infvenacava
is double only below the
level of renal veins.
a)Both channels may be
present on the right side
due to persistence of
both the subcardinaland
supracardinalveins below
the level of kidneys.
b)There may be additional
channel on the left side.

15. •Left infvenacava:
The infrarenalpart
of the venacava
may be present on
the left side only.

16. •Azygoscontinuation of
infvenacava:
The hepatic segment of
the infvenacavamay
be absent.
In such case, upper
part of the infvenacava
follows the course of
the azygosvein and
opens into the superior
venacava.

17. •Pre uretericvenacava:
Infvenacavanormally lies
posterior to the right ureter.
If it is anterior to the rt. ureter,
it may hook around the left side
of the venacava.
This anomaly is caused when
the infra renal part of the
venacavadevelops from the
subcardinalvein instead of
supracardinalvein.

18. Pulmonary veins
•The pulmonary veins are
those structures that form
independently, rather than
from the portions of the
cardinal venous system.
•When the septum primumis
just beginning to form, a
single pulmonary vein opens
into the left atrium.

19. •The single pulmonary vein now divides into
rt. and left branch.
•Each of these veins again bifurcates to drain
the corresponding lung bud.

20. •Gradually the parts of
the pulmonary veins
nearest to the left
atrium are absorbed
into the atrium.
•As a result four
separate veins, two
from each side, come
to open into the left
atrium.

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© 2005 Elsevier

22. Summary
•Formation of Infvenacava:
1.Lowest part of the rt
posterior cardinal vein and
the anastomosisbetntwo
posterior cardinal veins.
2.Lowest part of the
rt.supracardinalvein
3.Rt. Supracardinal-
subcardinalanastomosis.
4.Right subcardinalvein
5.Subcardinal-hepatocardiac
anastomosis.
6.Rt. Hepatocardiacchannel.

23. •How the
Suprarenal vein
formed??
•How the Gonadal
veins formed??
•Nature of
termination of
the veins on the
rtand left side??

24. •How the formation of pulmonary veins
occurs??

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