Vulva and Vagina Anatomy
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Direct answer
The vulva is the external female genitalia, extending from the mons pubis to the perineum, while the vagina is a fibromuscular canal lined by non-keratinised stratified squamous epithelium that runs from the vestibule to the cervix. The vestibule receives the urethral and vaginal openings. Lymphatic drainage of the vulva goes first to the superficial inguinal nodes, which governs the staging of vulval cancer.
What you must remember
- Vulval components: mons pubis, labia majora and minora, clitoris, the vestibule with urethral and vaginal openings, and the vestibular bulbs.
- Greater vestibular glands: lie posterolaterally at the introitus, and duct blockage produces a Bartholin cyst or abscess.
- Vaginal length: about 7.5 cm on the anterior wall and about 9 cm on the posterior wall.
- Fornices: anterior, posterior and lateral, with the posterior fornix the deepest and lying next to the pouch of Douglas.
- Vaginal wall: non-keratinised stratified squamous epithelium rich in glycogen, which thickens under oestrogen and thins after menopause.
- Lymphatics: the vulva drains to superficial inguinal nodes, while the upper vagina drains to internal and external iliac nodes and the lower third to superficial inguinal nodes.
- Innervation: the vulva and lower vagina are supplied by the pudendal nerve, whereas the upper vagina has visceral supply, so upper vaginal pain is poorly localised.
Relations that decide the complaint
A woman with a painful introital swelling or a deep vaginal bulge needs the structures beside the lesion. The table lists the relation that matters for each common complaint, and it is worth recalling row by row.
| Structure | Relation or content | Clinical point |
|---|---|---|
| Greater vestibular glands | Posterolateral at the introitus | Bartholin cyst or abscess |
| Posterior fornix | Lies next to the pouch of Douglas | Route for culdocentesis |
| Anterior vaginal wall | Bladder and urethra in front | Cystocele |
| Posterior vaginal wall | Rectum behind the rectovaginal septum | Rectocele |
| Lower vagina | Pudendal somatic supply | Perineal pain |
Each vaginal wall is separated from its neighbouring organ by fascia, so a weak fascial layer shows up as a specific prolapse. The anatomy therefore links directly to the symptom the patient describes, and examiners expect that link to be drawn in vignettes. Recalling the relation first narrows the differential before any examination or imaging is ordered, and it keeps the history focused on the right organ.
Where the exam tries to catch you
Vulva and vagina questions usually test which structure a lesion belongs to.
- Trap: Calling the Bartholin gland a part of the vagina. Correct: It is a vulval gland in the vestibule, so its cyst is a vulval swelling and not a vaginal one.
- Trap: Taking the posterior fornix to be shallow. Correct: It is the deepest fornix and the route for culdocentesis, because the pouch of Douglas lies just behind it.
- Trap: Expecting vulval cancer to spread first to pelvic nodes. Correct: Vulval carcinoma spreads first to superficial inguinal nodes, which is why groin node assessment is central to staging.
Frequently asked questions
Which glands produce lubricating mucus at the vestibule?
The greater vestibular (Bartholin) glands and the lesser vestibular glands produce mucus at the vestibule. The greater glands lie posterolaterally, and their duct blockage forms a cyst or abscess.
Which epithelium lines the vagina?
The vagina is lined by non-keratinised stratified squamous epithelium, which is rich in glycogen under oestrogen influence. This is why the vaginal epithelium thins after menopause and can cause atrophic symptoms.
Where does vulval cancer spread first?
Vulval carcinoma spreads first to the superficial inguinal lymph nodes, which drain the vulva directly. This is why inguinal node assessment is central to staging and to planning surgery in vulval cancer.
Which fornix is used for culdocentesis?
The posterior fornix is used for culdocentesis because it lies closest to the pouch of Douglas. Fluid aspirated through its wall can show free intraperitoneal blood or fluid.