Wednesday 12 September 2007
The cervix is typically 2.5 cm long. It communicates with the endometrial cavity of the corpus uteri through the internal os and with the vagina through the external os.
The vaginal portion (also called exocervix) is covered by stratified squamous epithelium, and the cervical canal is covered by columnar epithelium, which also forms endocervical glands, more correctly called clefts.
The 2 epithelia meet at the squamocolumnar junction. In most adult women, the squamocolumnar junction is not an abrupt meeting point, but a zone containing irregular areas of glandular and metaplastic squamous epithelium.
The size of this transformation zone varies from 2-15 mm. CIN usually arises in the transformation zone and usually extends to a depth of less than 7 mm.
The blood supply of the cervix originates mainly from the cervical branches of the uterine artery and from branches of the vaginal and pudendal arteries.
Histology of the uterine cervix (by Washington Deceit)
female genital system