Cervical canal

It corresponds to a slight constriction known as the isthmus that can be seen on the surface of the uterus about midway between the apex and base.

Prior to pregnancy, the external orifice has a rounded shape when viewed through the vaginal canal (as through a speculum).

The wall of the canal presents an anterior and a posterior longitudinal ridge, from each of which proceed a number of small oblique columns, the palmate folds, giving the appearance of branches from the stem of a tree; to this arrangement the name arbor vitae uteri is applied.

The cervical canal is generally lined by "endocervical mucosa" which consists of a single layer of mucinous columnar epithelium.

Endocervical adenocarcinoma, like cervical cancer (squamous cell carcinoma), often arises in the milieu of human papillomavirus infection.

Micrograph of an adenocarcinoma that arose from the endocervical mucosa. Pap stain .