Physiology

Question 1

What 2 specific components make up the placenta?

Answer 1

• Trophoblasts; surface layer of cells of the blastocyst.

- Decidual tissue; deep tissue of the endometrium.

Question 2

At what point during the pregnancy does the placenta and fatal heart become functional?

Answer 2

5th week

Question 3

Before the 5th week, what sustains the embryo?

Answer 3

HCG signals the corpus luteum to continue secreting progesterone; this stimulates decimal cells to concentrate glycogen, protein and lipids.

Question 4

What 3 fetal adaptations provide adequate supply of oxygen?

Answer 4

• HbF; increased capacity for carrying oxygen.
• Greater conc. of Hb; 50% more than adults.
• Bohr effect; HbF can carry more oxygen in low pCO2 than in high pCO2.

Question 5

What CVS adaptations occur during pregnancy?

Answer 5

• Increased CO.
• Increased HR.
• Reduced BP; during 2nd trimester.

Question 6

What 2 haematological changes can cause anaemia in pregnant women?

Answer 6

• Increased iron requirements.

- Hb decreased by dilution as erythropoiesis increases.