Vaginal fornices

Anatomy and formation

The vaginal fornices (fornices vaginae) are specific blind pockets. They are formed in the upper part of the organ, where the vaginal walls transition to the cervix protruding into its lumen. Traditionally, anatomy distinguishes the anterior and posterior fornices.

Interestingly, the prominence of these structures directly depends on the patient's age. In girls in the neutral period of development, the fornices are practically unexpressed. They complete their final formation later, becoming clearly visible and deep only in adult women.

In the middle section of the lesser pelvis cavity, the vagina itself changes its direction: it transitions from a vertical position to an angle relative to the pelvic axis, which also affects the spatial arrangement of the fornices.

Topography and relation to the peritoneum

The upper part of the vagina, where the fornices are located, has a critically important relation to the peritoneum. The peritoneal covering descends from the posterior surface of the supravaginal part of the cervix and passes onto the vagina.

At the same time, the peritoneum covers exclusively the posterior fornix for a length of 2 cm. Due to this anatomical feature, the posterior fornix, which is the deepest of all, directly borders the peritoneal cavity. Topographically, this zone corresponds to the rectouterine pouch (the so-called pouch of Douglas). The rest of the vagina is located lower, in the subperitoneal space of the pelvis.

Syntopy of the vaginal walls

To understand the topography of the fornices, it is important to know the syntopy of the adjacent vaginal walls:

• Anterior wall (paries anterior vaginae) closely adheres to the urinary bladder (in the upper sections it contacts its posterior wall) and the urethra (in the lower sections).
• Posterior wall (paries posterior vaginae) is adjacent to the rectum. In the middle section of the pelvis, they are separated by the dense rectovaginal septum (septum rectovaginale).
• Lateral walls are in contact with the elements of the urogenital diaphragm (diaphragma urogenitale). The fixation of the organ involves fibers of the deep transverse perineal muscle (m. transversus perinei profundus) and the medial bundles of the levator ani muscle (m. levator ani).

Clinical significance

The posterior fornix is of paramount importance in practical gynecology and surgery. Since it is covered by the peritoneum and closely adheres to the pouch of Douglas, diagnostic and therapeutic punctures are performed through it. This procedure allows rapid access to the abdominal cavity when intra-abdominal bleeding or an acute inflammatory process is suspected.

In addition, the close anatomical proximity of the vagina to the bladder anteriorly and the rectum posteriorly causes a risk of severe complications. As a result of injuries sustained during childbirth, pathological connections—fistulae (vesicovaginal or rectovaginal)—may form.

Blood supply and innervation

Tissues in the region of the fornices and vaginal walls receive a rich blood supply. Arterial inflow is provided by vaginal branches departing from the uterine artery (a. uterina) and the internal pudendal artery (a. pudenda interna). Venous blood drains into the dense vaginal venous plexus (plexus venosus vaginalis).

Lymphatic drainage and innervation of the upper parts of the vagina (including the fornices) are similar to those of the uterus. The lower part of the organ, up to the vaginal orifice (ostium vaginae), receives innervation from branches of the pudendal nerve (n. pudendus).

Class and exam questions

What else to study on this topic

• Syntopy of the vagina: relation to the urinary bladder and rectum
• Urogenital diaphragm and muscles fixing the vagina
• Blood supply and venous outflow from the pelvic organs
• Innervation of various parts of the vagina
• Anatomy of the vaginal introitus and hymen

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.