Studies on quantitative morphology. XII. Distribution of thyroid gland compartments in an activated rabbit thyroid gland.

A series of longitudinally cut step sections with a distance of 50 microns of a rabbit thyroid gland was measured by point counting for the relative tissue elements colloid, epithelium, and interstitium. Furthermore, the ratio epithelium:colloid was computed, which was somewhat high, indicating an activated stage. Higher colloid data were found in the outer regions and insignificantly lower epithelium values. Neither the volume data nor the distribution of the structure elements show any difference between both of the lobes. The degree of heterogeneity was comparably low, but only about 30% of all data for the relative colloid percentages or for the ratios are enclosed in a range of +/- 5% in relation to the most accurate value from all hits all over the gland, and about 20% of the ratio data are crossing the +/- 20% borderlines. It was calculated that measuring of not more than 5 sections with approximately equal distances with a very few 10(3) hits yields values of an acceptable accuracy for all parameters and this with a reasonable time expense.