Fetal circulation

Question 1

Major goal of fetal circulation

Answer 1

to get nutrients and oxygen to the brain and rest of body

Question 2

which systems are not yet functional in fetus

Answer 2

pulmonary and digestive systems, lungs are still collapsed and fluid filled

Question 3

how do fetus receive oxygen and nutrient?

Answer 3

from mothers placenta via diffusion

Question 4

Fetal circulation: starting point

Answer 4

• Placenta- diffusion of wastes, oxygen and nutrients

Question 5

oxygenated blood returns to fetus via….

Answer 5

umbilical vein

Question 6

deoxygenated blood leaves fetus via…

Answer 6

umbilical arteries

Question 7

getting to the heart: (most blood/ path 1)

Answer 7

Umbilical vein to ductus venosus and then to the inferior vena cava to heart (skips liver)

Question 8

getting to the heart: (path 2)

Answer 8

umbilical vein to portal sinus to liver and then portal vein. to heart (provide oxygen to liver)

Question 9

in fetal circulation what chamber does the blood enter….

Answer 9

right atrium

Question 10

Fetal circulation: through the heart (after entering the right atrium)

Answer 10

• 30% of blood is shunted to left atrium via the foramen ovale
  -70% of blood is pumped into right ventricle then to pulmonary artery then 90% of the blood enters the ductus arteriosus and is shunted to the aorta

Question 11

what organ is bypassed in fetal circulation?

Answer 11

lungs

Question 12

what structures helps to bypass the pulmonary circuit of. the fetus

Answer 12

-foramen ovale
- ductus arteriosus

Question 13

what happens if ductus arteriosus fails to close after birth?

Answer 13

• blood will flow back from aorta into pulmonary arteries