Literature search
The medical literature was searched electronically and manually for the
gross and topographic anatomy of the vaginal introitus, vaginal
vestibule, vaginal orifice, and vaginal outlet. In addition, anatomy
articles, conference proceedings, and specializing websites were also
included. The Medical Subject Headings (MeSH) were applied. The
following keywords or phrases were used: the human vagina, vaginal
outlet gross human vaginal outlet topographic anatomy, human vaginal
introitus gross anatomy, human vaginal topographic anatomy, human
vaginal orifice gross anatomy, human vaginal orifice topographic
anatomy, perineal body location, vaginal posterior-distal laceration,
vaginal outlet (vaginal introitus, and vaginal orifice) histology,
posterior vaginal colporrhaphy.
Results Anatomy
The vaginal outlet wall was in the anatomical region of the external
genitalia between the membranous urethral sphincter anteriorly, the
fossa navicularis posteriorly, and laterally. It was connected to the
labia minora. The deep segment (the hymeneal plate) of the vaginal
outlet wall fused directly with the vaginal wall and was topographically
positioned in the vertical orientation in the direction of a) superiorly
towards the vaginal canal; b) inferiorly to the fossa navicularis; c)
anteriorly towards the posterior perineal urethra; d) laterally to the
surface of the inner labia,
Fig. 1B.
Grossly, the vaginal outlet wall was the distal ending of the vaginal
wall and showed a different anatomical structure than the vaginal wall.
Furthermore, it was the narrowest part of the vagina. The vaginal outlet
wall was naturally slightly projecting outward, and it appeared as a
“belt-like” structure surrounding all vaginal walls (the anterior,
posterior, and lateral), Fig. 1B. The crease separated the vaginal
outlet wall a) anteriorly by the inferior membranous urethral sphincter;
b) posteriorly by the fossa navicularis; c) laterally by the labia
minora. The vaginal outlet wall was a monolithic structure composed of
three layers, Fig. 1, Fig. 2. The vaginal outlet ring layer demonstrated
much less elasticity to palpations than the vaginal walls and the
hymeneal plate. After dissecting the soft tissue of the hymen, the
hymeneal ring looked like smooth, white tissue and macroscopically
resembled cartilage. Superiorly, this elastic cartilage was fused with
the soft tissues of the hymeneal membrane and inferiorly with the hymal
plate. Such a subdivision of the vaginal outlet wall into the layers was
somewhat arbitrary but valuable for comprehension. The hymeneal ring
rested on the hymeneal plate, and both structures created a
protuberance. The hymeneal plate was a mixture of soft to palpation,
elastic, muscular, connective tissues, and reddish, and had more
stretchable tissues than the hymeneal ring,
Fig. 1B.