The epithelium of the vagina, visible at top, consists of multiple layers of flat cells.
The vaginal epithelium
is the aglandular
inner lining of the vagina
consisting of multiple layers of (squamous
) cells. The basal membrane provides the support for the first layer of the epithelium-the basal layer. The intermediate layers lie upon the basal layer and the superficial layer is the outermost layer of the epithelium. Anatomists have described the epithelium as consisting of as many as 40 distinct layers. The mucous found on the epithelium is secreted by the cervix and uterus. The rugae of the epithelium create a involuted surface and result in a large surface area that covers 360 cm3
. This large surface area allows the trans-epithelial absorption of some medications via the vaginal route.
In the course of the reproductive cycle
, the vaginal epithelium is subject to normal, cyclic changes, that are influenced by estrogen
: with increasing circulating levels of the hormone
, there is proliferation of epithelial cells along with an increase in the number of cell layers. As cells proliferate and mature, they undergo partial cornification. Although hormone induced changes occur in the other tissues and organs of the female reproductive system, the vaginal epithelium is more sensitive and its structure is an indicator of estrogen levels. Some Langerhans cells
are also present in the epithelium. The epithelium of the ectocervix
is contiguous with that of the vagina, possessing the same properties and function. The vaginal epithelium is divided into layers of cells, including the basal cells
, the parabasal cells, the superficial squamous flat cells
, and the intermediate cells. The superficial cells exfoliate
continuously and basal cells replace the superficial cells that die and slough off from the stratum corneum
. Under the stratus corneum is the stratum granulosum
and stratum spinosum
. The cells of the vaginal epithelium retain an usually high level of glycogen compared to other epithelial tissue in the body. The surface patterns on the cells themselves are circular and arranged in longitudinal rows. The epithelial cells of the uterus possess some of the same characteristics of the vaginal epithelium. Read more...