Anatomy of Cervix
The cervix is the lower fibromuscular portion of the uterus. It is cylindrical or conical in shape, and measures about 2.5-3cm in length. It protrudes into the vagina through its anterior wall and the upper half remains above the vagina. The portion of the cervix lying exterior to the external os is called the ectocervix and the portion proximal to the external os is called the endocervix. Normally a large area of ectocervix is covered by a stratified non- keratinizing glycogen containing squamous epithelium. It is opaque, has multiple (15-20) layers of cells and pale pink in colour. The endocervix is lined by the columnar epithelium. It is composed of a single layer of tall cells.