The sequence of reticularisation of epithelium of human palatine tonsil: scanning electron microscopic study.

The changes appearing during the development of the human palatine tonsil, both in the surface and in the tonsillar crypt epithelium, were studied from samples of the 16th to 40th prenatal weeks. From the 18th week, we observed areas of mesh-like epithelium in an originally homogeneous stratified squamous epithelium, i.e. the reticularisation began in the tonsillar crypt epithelium. The important role of the epithelial basal membrane in this process is discussed. The diffuse spongy-form type of reticularisation as well as the formation of the intraepithelial passages between the epithelial columns are described. The lymphoid cells and macrophages migrated through these microcrypts and they were frequently seen near the crypt epithelial micropores on the surface of the reticularised epithelium.

Relationship between the development of lymphatic and glandular tissue in the larynx.

A total of 144 human larynxes, both from the prenatal period and from subjects aged from birth to 95 years, were used for the study of the relationship between the development of glandular tissue and the localization of future laryngeal tonsils. The results of our study are represented graphically. It has been found out that at the sites of future tonsils glands make earlier appearance than at the sites of other glandular groups in the larynx. This interrelationship of lymphatic and glandular tissue has not only morphological but also clinical and immunological importance.