Vagina Embryological development:
– Upper ¾ : from Mullerian duct.
– Lower ¼ : from urogenital sinus.
Vagina 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.
Vagina 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.
Vagina 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.
Vagina Nerve supply:
Upper 2/3: like the uterus.
Lower 1/3: like the vulva (pudendal nerve, sensory).
Vagina Lymphatic drainage:
Upper 1/3: like the cervix.
Middle 1/3: to both directions.
Lower 1/3 : inguinal L.Ns.
Vagina ( Embryology – Anatomy – Histology ) Videos:
Dr. Evans: vagina anatomy video
Introduction to Female Reproductive Anatomy – 3D Anatomy Tutorial video
Reproductive System, part 1 – Female Reproductive System: Crash Course video
Vagina ( Embryology – Anatomy – Histology ) power point presentations:
Anatomy Of Female Genital Tract
Anatomy physiology of female reproductive system