Cervix carcinoma arises from :
Ans. is a i.e. Squamo-columnar Junction The cervix is lined by columnar epithelium which lines the endocervix (supravaginal pa of cervix) and squamous epithelium which lines the ectocervix (vaginal pa of cervix). The point at which they meet is called as Squamo-Columnar Junction (SCJ). The SCJ originally lies at the level of External OS. With response to hormonal stimulation the subcolumnar reserve cells present below the squamous epithelium undergoes metaplasia and replace the columnar epithelium. Thus location of SCJ is not fixed but keeps migrating and this called as Translormatior) cone The original SCJ can be recognized by Gland openings and Nabothian cysts. "Nearly all cervical neoplasia, boh squamous and columnar develop within the transformation zone, usually adjacent to the new SCJ." This is because theoretically, cervical cells underging metaplasia are more vulnerable to the oncogenic effects of HPV and cocarcinogens. Metaplasia is most active during adolescence and pregnancy that is why early age of sexual activity and first pregnancy are known risk factors for cervical cancer. In women exposed to Diethylstilbesterol (DES) in utero, the original SCJ is located on the vagina rather than on the cervix.
Squamo-columnar junction
Isthmus
Cervical lip
Internal os