<P> The cervix or cervix uteri ( Latin : neck of the uterus ) is the lower part of the uterus in the human female reproductive system . The cervix is usually 2 to 3 cm long ( ~ 1 inch ) and roughly cylindrical in shape , which changes during pregnancy . The narrow , central cervical canal runs along its entire length , connecting the uterine cavity and the lumen of the vagina . The opening into the uterus is called the internal os , and the opening into the vagina is called the external os . The lower part of the cervix , known as the vaginal portion of the cervix ( or ectocervix ) , bulges into the top of the vagina . The cervix has been documented anatomically since at least the time of Hippocrates , over 2,000 years ago . </P>
<P> The cervix or cervix uteri ( Latin : neck of the uterus ) is the lower part of the uterus in the human female reproductive system . The cervix is usually 2 to 3 cm long ( ~ 1 inch ) and roughly cylindrical in shape , which changes during pregnancy . The narrow , central cervical canal runs along its entire length , connecting the uterine cavity and the lumen of the vagina . The opening into the uterus is called the internal os , and the opening into the vagina is called the external os . The lower part of the cervix , known as the vaginal portion of the cervix ( or ectocervix ) , bulges into the top of the vagina . The cervix has been documented anatomically since at least the time of Hippocrates , over 2,000 years ago . </P>
the opening of the uterus is referred to as
the opening of the uterus is referred to as
internal os
internal os