Morphometry of the Placental Exchange Area

by R. Baur

Overview

Considering the placenta from the functional point of view as an exchange organ be- tween mother and foetus, it is noteworthy that placentas of all types have a common structural principle in that all placentas have structures enlarging the surface area avail- able for exchange, as is also the case with other organs with similar functions, such as the lungs, kidneys and intestine. It may therefore be assumed that a quantitative rela- tionship must exist between the structure of the placenta and its function. Accurate information on this relationship could contribute to better understanding of the pla- centa and of its function. The study of this relationship requires quantitative physio- logical and morphological data. Detailed data on quantitative morphology (morphometry) are available mainly for the human placenta. Even these data, however, are rather sparse as far as the early sta- ges of development are concerned, because most-studies relate to full term placentas (see Aherne, 1975; Bender et al., 1974; Laga et aI., 1973; Geissler et aI., 1972; Baur, 1972; Cattoor, 1967; Aherne and Dunnill, 1966). We know of only a few morphomet- ric studies concerned with placentas of other animal species. These studies relate to in- vestigations on the development of the placenta of sheep (Stegeman, 1974) and of cat- tle (Baur, 1972), and measurements carried out on full term placentas of the guinea- pig (Millier et aI., 1967) and on full term placentas of various other species (Baur, 1973).

Product Details

ISBN-13:	9783540081593
Publisher:	Springer Berlin Heidelberg
Publication date:	06/02/1977
Series:	Advances in Anatomy, Embryology and Cell Biology , #53
Pages:	65
Product dimensions:	6.10(w) x 9.25(h) x 0.01(d)

Table of Contents

A. Introduction.- B. Materials and Methods.- 1. Materials.- 2. Contributors.- 3. Nomenclature.- 4. Measurement Methods.- 5. Evaluation.- C. Findings.- 1. Growth of the Total Villous Surface Area.- 2. Transformed Values of Areas and Volumes.- 3. Variation of the Area/ Volume Ratio with Time.- 4. Relative Villous Surface Area.- 5. Volume of the Compact Parts of the Placenta.- 6. Surface Density.- 7. Macroscopic Chorionic Surface Area.- 8. Surface Enlargement Factor.- 9. Area/Volume Ratios in Full Term Placentas.- D. Discussion.- 1. Smoothing Curves and Function Equations.- 2. Compact Parts of the Placenta and Surface Density.- 3. Macroscopic Chorionic Surface Area and Surface Enlargement Factor.- 4. Model of the Growth of the Total Villous Surface Area and of the Total Volume.- 5. Physiological Implications of the Area/Volume Ratio.- 6. Differences in the Size of the Villous Surface Area in Compact and in Diffuse Placentas.- 7. Morphometric Findings and Systematic Classification of Placentas.- E. Summary.- F. References.- G. Subject Index.