Sagittal Profile of the Cervical Vaginal Portion

Description

Visible in sagittal profile, the portio vaginalis cervicis projects inferiorly into the vaginal fornix, with the ectocervix (exocervix, outer portion) covered by nonkeratinized stratified squamous epithelium. Superior to this exposed vaginal portion, the endocervical canal continues toward the uterine cavity, creating a clear junction between the vaginal environment and the cervical stroma. Anterior and posterior cervical lips can be inferred in section, defining the contour that surrounds the external os. That epithelial boundary is the teaching point. The squamous lining of the ectocervix meets columnar epithelium of the endocervix at the squamocolumnar junction, and its migration into the transformation zone under estrogenic influence explains why cervical intraepithelial neoplasia and HPV-related dysplasia cluster at or near the external os. Colposcopy, Pap sampling, and LEEP or cold-knife conization all target this region, so a sagittal slice helps learners connect surface histology to what is actually sampled and excised. Gynecology and pathology faculty can drop this into lectures on cervical anatomy, screening, and the histologic basis of CIN grading, while medical publishers will find it a clean companion image for chapters on the cervix, vagina, and lower genital tract. It also supports patient-facing education on why a Pap test samples cells from the ectocervix and endocervical canal, not just the vagina. Anatomical accuracy verified by SciePro's Medical Advisory Board.