Medicine and Health related Information

In the foetus the blood of the body wall s drained by two pairs of cardinal veins, anterior and posterior cardinal veins. These two unite and forms common cardinal veins or duct of cuvier. These open into corresponding horns of sinus sinus venosus.
The two anterior cardinal veins communicate through anastamosis.
The posterior cardinal veins gradually disappears and these are replaced by a pair of supra cardinal veins. Now the body wall veins open into supracardinal vein.

Superior venacava-
It is developed from the right common cardinal vein and form right anterior cardinal vein, a tributary of right horn of sinus venosus. It opens into right atrium.
Coronary sinus-
Partly it is developed from the left horn of sinus and partly from the common cardinal vein.
Oblique vein of the left atrium- develops from the left common cardinal vein.
Left superior venacave- sometimes left common cardinal vein may persists as left superior venacava.

Azygos vein-
The upper most part develops from the right posterior cardinal vein, the lower part by right supra cardinal vein.

Hemi-Azygos vein-
On the left side it is formed by the left supra cardinal veins.