Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Jun 8, 2012
By, Prof. Graham Burton, Head, Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom
Placental stereology; from sections to morphometric diffusing capacity
The placenta performs many functions, but nutrient and gaseous exchange between the mother and her fetus is obviously one of the most important for normal fetal growth. Estimating the transport capacity of the placenta can therefore help separate placental from fetal causes of intrauterine growth restriction. Equally, researchers may wish to explore developmental mechanisms by which the placenta can adapt to increase its transport capacity under adverse conditions, such as at high altitude or when maternal blood flow is limiting.
Transfer of oxygen occurs by simple diffusion, and so the rate is governed by the Fick equation. Diffusion across the villous membrane has been calculated to account for approximately 90% of the overall resistance to oxygen flow from maternal to fetal haemoglobin. Stereological estimates of the total surface area and harmonic mean thickness of the villous membrane can be used to derive the morphometric diffusing capacity. Experiments in animal models have shown a close correlation between these estimates and measurements derived physiologically in vivo.
In this webinar, I will run through how one can derive the morphometric diffusing capacity for both the human and mouse placenta.