Anatomy, Histology, Cytology, and Colposcopy of the Cervix

The cervix represents the lower portion of the uterus and plays an important anatomical role in supporting the internal genital organs during pregnancy and at birth. It also has importance as a cervical mucin-producing organ. The cervical stroma comprises a mixture of fibrous, muscular, and elastic tissue. It is lined by a columnar epithelium in the endocervical canal and by a mature, nonkeratinizing squamous epithelium in the ectocervix. The location of endocervical epithelium varies throughout life and is influenced by the hormonal milieu, such that endocervical epithelium can be visualized by colposcopy in women of reproductive age. The “transformation zone” encompasses a junctional area, containing combinations of glandular and metaplastic squamous epithelium, bounded proximally by endocervix and, distally, by ectocervix. This is considered to be the area where most neoplastic processes occur.