from fetus to infant

Question 1

Name 6 roles of the placenta

Answer 1

1) site of oxygen transfer
2) provides nutrition
3) provides growth hormones
4) controls fluid and electrolyte balance
5) undertakes waste removal
6) allows IgG to pass into fetus

Question 2

what 3 factors allow effective donation to and use by the fetus

Answer 2

• lower PaO2 in umbilical arteries than maternal circulation (o2 gradient)
• higher affinity of HbF than HbA to facilitate uptake of O2
• Higher Hb in fetus for effective carriage and release of oxygen

Question 3

What vessel leads from the placenta to the fetus

Answer 3

umbilical vein

Question 4

what vessel leads from the fetus to the placenta

Answer 4

umbilical arteries (arise from internal iliacs)

Question 5

Name 3 structures in the fetal circulation that differ in the adult circulation

Answer 5

• Ductus arteriosus
• Foramen Ovale
• Ductus venosus

Question 6

What respiratory changes occur with the first breath

Answer 6

• lungs expand and alveoli are patent
• establish FRC
• lung liquid removed

Question 7

what changes happen to pulmonary blood flow

Answer 7

reduced pulmonary resistance
increased blood flow to the lungs
closure of foramen ovale

Question 8

What changes occur to the

a) umbilical vein
b) ductus venosus
c) foramen ovale
d) ductus arteriosus
e) umbilical arteries

Answer 8

a) becomes ligamentum teres and mesentery becomes falciform ligament
b) constricts and all blood goes through hepatic sinusoids
c) closes due to pressure in LA
d) closes by increases in PaO2 and becomes ligamentum arteriosum
e) constrict