Cervical canal

Cervical canal
Posterior half of uterus and upper part of vagina
Details
Synonym	Canal of the cervix, endocervical canal, cervical canal of uterus, cavity of cervix
Identifiers
Latin	canalis cervicis uteri
TA	A09.1.03.018
FMA	86485
Anatomical terminology [edit on Wikidata]

The cervical canal is the flattened canal going through the cervix. The cervix is the lower part of the uterus.

The cervical canal is a tube that connects with the uterine cavity through the internal os with the vagina through the external os. The internal os is smaller than the external os. The external os is a small, circular opening on the rounded end of the cervix. The external os opens into the vagina. The cervical cavity is located at the top of the vagina. The external os is surrounded by two lips, an anterior lip and a posterior lip. The anterior lip is shorter and thicker. Both lips are touching the vaginal wall. Before pregnancy, the external os has a rounded shape. After pregnancy the os changes shape.

The squamocolumnar junction of the cervix: The ectocervix, with its stratified squamous epithelium, is visible on the left. Simple mucinous columnar epithelium, typical of the endocervix, is visible on the right. A layer of connective tissue is visible under both types of epithelium.

Transformation zone types:^[1]
Type 1: Completely ectocervical (common under hormonal influence).
Type 2: Endocervical component but fully visible (common before puberty).
Type 3: Endocervical component, not fully visible (common after menopause).

The cervical canal is lined by a tissue called the "endocervical mucosa". This consists of a single layer of mucinous columnar epithelium. After menopause the tissue goes through changes.^[2]

The endocervical mucosa is one place tissue from where cervical cancer (adenocarcinoma) can grow. Endocervical adenocarcinoma, like another cervical cancer (squamous cell carcinoma), often grows from human papilloma virus infection.^[3]

• Cervical pregnancy