Cervical canal

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

Anatomy
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 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.

Pathology
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.

Related pages
 Cervical pregnancy

References

Category:Anatomy of the female reproductive system