Special Circulation: Maternal-Fetal

Question 1

What happens to blood volume in pregnancy?

Answer 1

Increases 20-100%

Question 2

What is physiologic anemia of pregnancy?

Answer 2

Plasma increases more so than hematocrit causing relative anemia

Question 3

What happens to CO in pregnancy?

Answer 3

Increases

Question 4

What causes an increase in CO?

Answer 4

Initially increased SV

Later on increase in HR

Question 5

What happens to BP during pregnancy?

Answer 5

Decrease in systolic

Great decrease in diastolic

Question 6

Why does BP decrease in pregnancy?

Answer 6

Increase in circulating vessels and vasodilation

Question 7

What causes supine hypotensive syndrome?

Answer 7

When the mother is lying down the fetus can collapse the IVC reducing venous return and cardiac output

Question 8

What are the four unique shunts in fetal circulation?

Answer 8

Placenta
Ductus venosus
Foramen ovale
Ductus arteriosus

Question 9

How does the fetal heart pump?

Answer 9

In parallel as apposed to series

Question 10

What is combined cardiac output?

Answer 10

The sum of outputs of the right and left ventricles

Question 11

What organs does the placenta function as?

Answer 11

Lungs
GI tract
Liver
Kidneys

Question 12

Where does half of the CCO go?

Answer 12

Placenta

Question 13

What does the ductus venosus do?

Answer 13

Bypasses liver to deliver oxygenated blood from umbilical vein into IVC

Question 14

Which vessels have the highest hemoglobin saturation?

Answer 14

Umbilical vein and ductus venosus

Question 15

What causes high resistance in the fetal lungs?

Answer 15

Hypoxic vasoconstriction and acidosis

Question 16

How does epinephrine work in neonate thermogenesis?

Answer 16

Acts through a GPCR to activate PKA to produce free fatty acids

Question 17

How does brown fat produce heat?

Answer 17

Free fatty acids unblock the uncoupling proteins (UCP) that are normally blocked by ATP and GTP allowing H+ into the mitochondrial matrix where heat is produced without shivering