Healthy cervix. Colposcope image of a normal, healthy cervix. The pale, pink doughnut shaped entrance to the cervical canal is at centre. The speculum (silver) can be seen at upper and lower centre, holding back the vaginal walls. The cervix is a small, cylindrical organ, several centimetres in length and 2.5 centimetres wide. It comprises the lower part and neck of the uterus, separating the body of the uterus and the vagina. Running the length of the cervix is the cervical canal through which blood passes during menstruation. The canal also forms part of the birth canal during childbirth.