fetus oxygen association

Question 1

what is special about fetus haemoglobin

Answer 1

-it has a higher affinity for oxygen at any partial pressure

Question 2

why is fetal haemoglobin adapted in this way

Answer 2

-it must be able to associate with oxygen where the partial pressure is low enough to make maternal haemoglobin release

Question 3

what encourages the dissociation of oxygen from maternal blood cells

Answer 3

-in the placenta, the partial pressure is low but fetal hb will still absorb 02
-further reducing p02 of maternal plasma
-more 02 diffuses from mothers blood into plasma
-reduces partial pressure in mothers blood
-further encourages dissociation of 02 from maternal blood cells