There are 3 pairs of veins at 5th week of intrauterine life
1)Vitelline vein(visceral)
2)Umbilical vein(visceral)
3)cardinal vein(somatic)
Vitelline Vein :
- Also known as Omphalo-mesentric veins
- Drains yolk sac to sinus venosus in heart
- However before entering into sinus venosus it forms plexus around duodenum which later forms PORTAL Vein.
- This plexus enters liver and divides in multiple veins to end in hepatic sinusoids.
- This sinusoids are drained into sinus venosus by hepatocardinal channels.
- Left hepato cardinal channels and distal portion left vitelline vein disappears gradually.
- Remaining proximal portion of left vitelline vein forms HEPATIC VEIN
- Right hepatocardinal channels forms hepatic part of INFERIOR VENA CAVA
- Right vitelline vein forms SUPERIOR MESENTRIC VEIN
Umbilical vein
(will discuss fate of U.artery too)
- Initially 2 arteries and 2 veins in umbilival cord
- @ 4 months of intraiterine life,Right umbilical vein disappears so remains 2 arteries and 1 vein
- Left umbilical vein communicates with hepatocardinal channels via ductus venosus
- Left umbilical vein changes to ligamentum teres
- Ductus venosus changes to ligamentum venosum
- Proximal portion of umbilical arteries form superior vesical artery and distal portion forms medial umbilical ligament
Cardinal Vein
- Drains embryo proper
Formation of SUPERIOR VENA CAVA
- from right anterior cardinal vein
- and right common cardinal vein
Formation of INFERIOR VENA CAVA
- Hepatic part - Right hepatocardinal veins
- Prerenal part - right subcardinal vein
- Renal part - right subcardinal-supracardinal anastomosis
- Post renal part - right posterior cardinal vein
