Final answer:
The region of the vagina surrounding the cervix is the fornix.
Step-by-step explanation:
The region of the vagina that surrounds the cervix is known as the fornix. The vagina is an elastic, muscular canal that plays a crucial role in the female reproductive system. It connects to the external genitalia at one end and to the cervix of the uterus at the other. The outer walls of the vagina contain longitudinal columns or ridges, and it is the superior portion of the vagina, the fornix, which meets the protruding uterine cervix. This region allows for the expansion of the vagina during intercourse and childbirth, thanks to its layered structure, which includes a fibrous adventitia, a layer of smooth muscle, and an inner mucous membrane with transverse folds known as rugae.