Vagina ( Embryology – Anatomy – Histology )

By posted on December 15, 2017 12:58PM

Vagina ( Embryology – Anatomy – Histology )

Embryological development:
– Upper ¾ : from Mullerian duct.
– Lower ¼ : from urogenital sinus.
Description:
Site : Connects the uterus above with the vestibule below.
Size : * Anterior wall= 7.5 cm. * Posterior wall = 10 cm.
Direction: Runs upward backward making angle 60 ͦ with the horizontal plane.
Relations:
Anteriorly :
· Upper ⅓: trigone of U.B. (Back of urinary bladder).
· Lower ⅓: urethra (runs from above downwards).
Posteriorly :
· Upper ⅓: peritoneum of Douglas pouch containing loops of intestine.
· Middle ⅓: ampulla of rectum comes closer to vagina.
· Lower ⅓: perineal body separating vagina anteriorly from anal canal posteriorly.
Laterally :
· Upper part : uterine vessels run above ureter.
· Middle part: levator ani & pelvic fascia above it.
· Lower part :
* 1cm above orifice: urogenital diaphragm.
* Lower end : bulbocavernosus muscle, vestibular bulb & Bartholin gland.
Superiorly :
· Vaginal portion of cervix is surrounded by 4 vaginal fornices:
– Anterior fornix: shallow & lies between cervix & anterior vaginal wall.
– Posterior fornix: deep & lies between cervix & posterior vaginal wall.
– 2 lateral fornices: lies between cervix & lateral vaginal wall.
Inferiorly:
· Closed by hymen in virgins.
N.B.
* Crossing of uterine artery to the ureter lies 1.5 cm above vaginal vault & 1.5 cm
lateral to the cervix.
* Above this crossing: paracervical L.N. & paracervical nerve ganglion are present.
Vaginal support:
1. Ligaments supporting cervix & attached to upper vagina.
· Anterior Pubocervical ligament.
· Lateral Mackenrodt’s ligament.
· Posterior Uterosacral ligament.
2. Pubovaginalis part of levator ani muscle.
3. Pelvic diaphragm (triangular ligament).
4. Perineal membrane.
5. Vaginal fascia.

Diagrams showing the layers of the vaginal wall

Histology (fibromuscular tissue):
* Cut section: H-shaped with approximation of anterior to the posterior vaginal wall.
* Layers:
– Mucosa: – Non-keratinized stratified squamous epithelium.
– No glands, but kept moist by vaginal transudation & cervical mucus secretions.
– PH around 4.5 (WHY?!!!)
– Thrown into rugae (folds), this allows distension of vagina during labour.
N.B: Vaginal adenosis
Def.: presence of glands into vagina.
A/E: exposure to DES (DiEthyl Stilbisterol) in utero.
Comp.: precancerous (clear cell carcinoma)
– Submucosa: connective tissue rich in:
– Blood vessels, nerves & lymphatics. &
– Elastic fibers to allow great distension.
– Musculosa: * Smooth muscle fibers arranged in criss-cross manner.
* Some fibers from levator ani are inserted into it.
– Adventitia: dense C.T. sheath forms: *Anteriorly Pubocervical fascia.
*Posteriorly Rectovaginal fascia.

Blood supply:
A. Arterial:
Vaginal artery (branch of from internal iliac artery).
Lower part is supplied by numerous branches of internal iliac artery;
· Uterine artery : ……………………..……a branch of internal iliac artery.
· Middle rectal artery : ………………………… a branch of internal iliac artery.
· Inferior rectal artery:… from internal pudendal artery of internal iliac artery.
B. Venous:
Accompany corresponding arteries: drain into vaginal plexus then into internal iliac v.
Vaginal plexus connects with plexuses around bladder & rectum.

Nerve supply:
Upper 2/3: like the uterus.
Lower 1/3: like the vulva (pudendal nerve, sensory).

Lymphatic drainage:

Upper 1/3: like the cervix.
Middle 1/3: to both directions.
Lower 1/3 : inguinal L.Ns.

Dr. Evans: vagina anatomy video

Introduction to Female Reproductive Anatomy – 3D Anatomy Tutorial

Reproductive System, part 1 – Female Reproductive System: Crash Course

Vagina ( Embryology – Anatomy – Histology )

Source: Vagina ( Embryology – Anatomy – Histology )

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Dr.Galal Baligh

OB-GYN Specialist

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