求翻译：In inhalation studies, tracheal epithelium including the epithelial lining of the bifurcation should be examined, because this is known as the most sensitive area to respond to inhaled particulate irritants. For this purpose, a longitudinal horizontal section should provide a long distance of the epithelial surface and the tip of the carina. For optimal estimation of e.g. mild hyperplasia, it can be helpful to have an optional transverse section (see alternative trimming technique for oral toxicity study under thyroid gland/parathyroid gland/trachea).是什么意思？

待解决 悬赏分：1 - 离问题结束还有