The neck of the uterus is the cervix.
the aswer is
cervix
Cervix
the sperm reaches the uterus through the cervical opening or cervical os.
The cervix is the opening to the uterus, so you'd have to go through it to get to the uterus.
the internal OS
The opening of the cervix is closest to the vagina -- the one you can feel with your finger -- is called the external os (orifice). This os leads into the cavity of the cervix and then into the cavity of the body of the uterus. At the point where the endocervical canal meets the uterus is another opening, called the internal os. .
I believe the answer is prolapse of the uterus.
urethra
Cervix
It is the cervix.