Histometric Investigations in Placentones (Materno-Fetal Circulation Units) of Human Placentae

Abstract

The placenta comprises a variable number of about 50 (40–60) functional and circulatory units called “placentones” according to the investigations of Crawford (1956), Smart (1962), Wilkin (1965), Panigel et al. (1967), Freese, (1968a, 1968b), Freese and Maciolek (1969), Wigglesworth (1969), Reynolds (1966, 1967, 1971), Ramsey (1962, 1966, 1971), Ramsey et al. (1963) and earlier investigations in our own laboratory (Schuhmann, 1976). Concerning the histologic structure of these units especially their fetal part (lobuli) it was shown by Wigglesworth (1969) and by Crawford (1956a, 1956b) and by own investigations (Maier, 1985; Schuhmann and Wehler, 1971; Schuhmann, 1976; Schuhmann et al., 1979) that the villi in the centers are more loosely arranged than in the periphery. Referring to the histology of the villi in the different areas of the lobuli, Grunwald (1966, 1973) and Wigglesworth (1969) pointed out that there is a marked difference in the degree of differentiation between the central and the peripheral area. These findings were confirmed by Alvarez (1970), Crawford (1956b) and by own earlier investigations (Schuhmann et al., 1971, 1972, 1976, 1977; Schuhmann, 1976). With the development of new technical equipment it is now possible to measure and calculate what were only “impressions” by means of the classical histology. Therefore, this laboratories former histologic results were confirmed by means of histometry.