[katieHaylor (OP)]

Julia asks:

What organs/tissues is the umbilical cord connected to inside the foetus? What happens with them after the umbilical cord is cut?

Can you help?

[Bigjoemonger]

There's a hole in the wall of the heart separating the left and right ventrical. This causes blood to bypass the lungs. When the baby is born and the umbilical is severed the hole gets sealed which redirects the blood to the baby's lungs allowing it to breathe on its own.

The umbilical cord has two arteries and a vein. Carrying oxygenated and nutrient filled blood to the fetus and bringing back de-oxygenated blood and waste back to the mother.

In a post-birth person there is a clear split between arteries carrying oxygenated blood and veins carrying deoxygenated blood but because the lungs are bypassed the fetus' blood is of mixed oxygenation, with the heart pumping mostly deoxygenated blood in the umbilical arteries and bringing back oxygenated blood in the umbilical vein.

The umbilical vein connects to the fetal liver and the inferior vena cava and the umbilical arteries branch off the iliac arteries and pass by the bladder to pick up waste before going to the placenta.