Comparison of the gross anatomy and epithelium in the genital tract in women and pigs. The porcine uterus differs macroscopically from the human simplex uterus by having bilateral horns (bicornuate) . The porcine cervix displays a characteristic feature, not found in women; the cervical pulvini (red arrow) . Furthermore, the porcine urethra opens on the ventral surface of the vagina (purple arrow) creating an urogenital sinus that opens to the outside through the common urogenital orifice . In women, the urethra and vagina have its own separate openings to the outside . Otherwise the porcine vagina is similar to the human one . The human cervix is divided into the ectocervix that protrudes into the vaginal canal and the endocervix, creating the cervical lumen. An example of the local immune system in the female genital tract is shown at the transition between the ecto- and endocervix.