Foetal Circulation

Question 1

In the foetal heart, what connects the umbilical vein (coming from placenta) to the IVC?

Answer 1

Ductus venosus

Question 2

What is the importance of the ductus venosus?

Answer 2

Allows most of the blood from placenta to bypass the liver and go straight to heart

Question 3

In the foetal heart, what connects the right atrium to the left atrium?

Answer 3

Foramen ovale

Question 4

What is the importance of the foramen ovale?

Answer 4

Enables oxygenated blood entering RA (from IVC from umbilical vein from placenta) to enter LA, bypassing pulmonary circulation, i.e. oxygenated blood is not sent to the lungs

Question 5

Once oxygenated blood has moved through the foramen ovale, where does it go?

Answer 5

Enters LV and pumped into the aorta to the body, importantly the brain

Question 6

In the foetal heart, what connects the pulmonary artery to the descending aorta?

Answer 6

Ductus arteriosus

Question 7

What is the importance of the ductus arteriosus?

Answer 7

Enables deoxygenated blood pumped through pulmonary artery to enter descending aorta to go to placenta to get oxygenated

Question 8

Do the lungs take part in gas exchange in the foetus?

Answer 8

No, hence why the pulmonary circulation is cleverly bypassed in the foetal heart

Question 9

What results in closure of the foramen ovale?

Answer 9

Baby’s first breath after delivery (usually)

Question 10

What is the remnant of the umbilical vein in adults?

Answer 10

Ligamentum teres

Question 11

What is the remnant of the ductus venosus in adults?

Answer 11

Ligamentum venosus