The cervix or cervix uteri refers to the lower portion of the uterus in the human female reproductive system. The openings are called the internal orifice and the external orifice of the uterus.
The internal orifice or internal os refers to the upper terminal of the cervix, which opens into the uterus. On the other hand, the external orifice refers to the terminal of the cervix, which opens into the vagina.
