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Cervix

The cervix, the lower portion of the uterus, consists of two main regions: the endocervix and the ectocervix. The endocervix, which lines the cervical canal, is composed of simple columnar epithelium with mucus-secreting glandular cells. These cells produce cervical mucus, which changes in consistency throughout the menstrual cycle to facilitate or inhibit sperm passage.

Histological slide of the cervix tissue. Red-stained mucus is spread across the surface with simple columnar epithelial cells. The tissue structure is composed of cells stained in red and connective tissues in blue, visualized under high magnification.
Figure 1: Microscopic view of the cervix. Simple epithelium lines the lumen with scattered mucus cells and a thick layer of mucus lining the lumen. At the bottom right of the picture are cervical glands
Cervix histology, Masson's trichrome stain showing glands and stroma.
Figure 2: Cervix histology, Masson’s trichrome stain showing glands and stroma.

In contrast, the ectocervix, which projects into the vagina, is lined by non-keratinized stratified squamous epithelium. This type of epithelium is well-suited to withstand mechanical stress and the acidic environment of the vagina. Between these two regions lies the transformation zone, also known as the squamocolumnar junction, where the columnar epithelium of the endocervix transitions to the squamous epithelium of the ectocervix. This area is of particular clinical importance, as it is the most common site for cervical dysplasia and the development of cervical cancer, especially in relation to human papillomavirus (HPV) infection.

Beneath the epithelial layers, the cervical stroma consists of dense connective tissue interspersed with smooth muscle fibers, blood vessels, lymphatics, and immune cells, all of which contribute to the structural support and immunological function of the cervix.

Figures 1 & 2: Cervix, trichrome stain, 40X Slide UCSF 405
All by University of Michigan Histology, licensed under CC BY-NC-SA 3.0.

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Epididymis
Accessory Glands
Seminiferous tubules
Penis
Vas Deferens
Vagina
Cervix
Uterine Tubules
Uterus
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Oocytes
Corpora (luteum and albicans)

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