A scanning electron microscope study of the fine angioarchitecture of the uterine cervix using a newly established cast formation technique

The vascular architecture of the supravaginal and vaginal parts of the human uterine cervix: a study using corrosion casting and scanning electron microscopy

The aim of this study was to visualize and describe the vascular architecture of the vaginal and supravaginal parts of the human uterine cervix. Uteri collected at autopsy (n = 42) were perfused via the afferent vessels with fixative followed by Mercox resin. After polymerization of the resin, corrosion was performed. The obtained vascular casts of the cervix, visualizing all vessels including capillaries, were examined using scanning electron microscopy. Both in the vaginal and supravaginal parts of the cervix, four distinct vascular zones were distinguished - the outer zone containing large arteries and veins, the arteriole and venule zone, the endocervical mucosal capillaries zone and the pericanalar zone containing small veins and capillaries. In the pericanalar zone ran small veins, responsible for draining the mucosal capillaries. Both in the muscular layer, as well as in the pericanalar zone, arterioles and venules passed close to each other, often adjoining. This study introduces the idea of two systems responsible for draining blood from the mucosal capillaries. It is also the first to suggest the possible existence of a countercurrent transport between adjoining veins and arteries.

Langerhans' cells and lymphocyte subsets in the female genital tract

Cryostat sections of healthy cervical, vaginal and vulval epithelium were examined using immunohistological labelling techniques and a panel of monoclonal antibodies recognizing Langerhans' cells, T- and B-lymphocytes and HLA-DR antigen. The distribution of Langerhans' cells in squamous epithelium of the cervix, vagina and vulva showed a marked variation with the highest median values in the vulva (18.7 per 100 basal squamous cells) and the lowest in the vagina (5.5 per 100 basal squamous cells). There was also a substantial variation in number and distribution of lymphocytes of each of these three areas with a distinct preponderance in the transformation zone of the cervix. In addition, intraepithelial lymphocytes, predominantly of the T-cytotoxic suppressor sub-type were present at all sites with the greatest number in the transformation zone. We conclude from this study that lymphoid tissue of the cervical transformation zone has several unique characteristics which are not observed at other sites in the lower genital tract. We suggest that this tissue be designated 'cervical lymphoid tissue' and that it forms a part of the 'mucosal associated lymphoid tissue' (MALT) as noted at other mucosal sites exposed to the external environment.