Description: A mathematical model of placental oxygen transfer is
used to argue that the experimentally observed control of
fetal oxygen concentration in fetal lambs can be explained
by the nature of oxyhemoglobin dissociation functions and
the differences between these functions in fetal and
maternal blood. It is not essential to the explanation
to posit any mechanisms responding to a PO2 sensor or any
changes in fetal, maternal, or placental vascular structures.
Equally unnecessary are assumed alterations in the physical
or chemical structure of placental membranes.
