The cervix is a cylinder-shaped neck of tissue that connects the vagina and uterus. Located at the lowermost portion of the uterus, the cervix is composed primarily of fibro muscular tissue. There are two main portions of the cervix:
The part of the cervix that can be seen from inside the vagina during a gynecologic examination is known as the ectocervix. An opening in the center of the ectocervix, known as the external os, opens to allow passage between the uterus and vagina.
The endocervix, or endocervical canal, is a tunnel through the cervix, from the external os into the uterus.