Vagina/ Birth canal
Vagina is called birth canal.
It is fibromusculo-membraneous sheath.
It communicating uterine cavity and exterior at vulva.
It excretory channel for uterine secretion and menstrual blood and also called birth canal of parturition (child birth/labour/delivery).
Diameter of Canal
About 2.5cm widest in upper part.
Narrowest in lower part (entrance).
Location
Urethral opening at the top.
Vaginal opening is in middle.
Anus opening at bottom.
Vagina is located between bladder and rectum.
Wall of Vagina
Wall of vagina made of muscle covered in mucus membrane.
Anterior vaginal wall; pubocervical facia, it’s covering epithelium.
Posterior vaginal wall
Two lateral vaginal wall
Length of Anterior wall about; 7cm
Length of Posterior wall about; 9cm
Fornices (Vaginal Tornicus, arch)
Superior portion of vagina/ widest part at end of vaginal canal, forming dome shape around cervix.
Four fornices present;
1. One anterior
2. One posterior
3. Two lateral
Vaginal Vault
Expanded region of vaginal canal at the internal end of vagina.
Associated Structure
1. Anterior
Base of bladder, urethra
2. Posterior
Pouch of Douglas (or rectovaginal pouch) between uterus and rectum. Rectal wall separated by rectovaginal septum and anal canal separated by perineal body.
3. Lateral wall
Bulbocavernosus muscles ( it cover vestibular bulb) vestibular bulbs and bartholin’s glands.
Function; it aids in the emptying of greater vestibular glands (bartholin’s glands) in female by constructing the vaginal orifice, facilitating clitoris erection.
Structure of Vagina
Vagina is hollow tube organ.
Layers of Vagina
1. Adventitia
Outer layer, made up of connective tissue.
Rich in collagen and elastic, provide structural support to vagina and allow expansion of vagina during child.
Consist of blood vessels lymphatic duct and nerve.
2. Muscularis
Middle layer, made up of muscle.
Arranged into;
Outer longitudinal layer
Inner circular layer
3. Mucosa
Inner mucosal layer, made up of squamous epithelium cell.
It transverse fold or rougae.
a. Lamina propria
Rich in elastic fibres, have having glands.
No mucus gland (without any secreting glands).
b. Non-keratinized stratified squamous epithelium
Arterial Supply
Upper vagina, supplied by vaginal branches of uterine artery.
Middle vagina; branch of hypogastric artery, vaginal artery (inferior vaginal artery).
Distal vagina, clitoral arteries
Cervicovaginal branch of uterine artery.
Vaginal artery; Branch of internal iliac artery
Middle rectal artery; arise from internal iliac artery
Internal pudendal artery
Nerve Supply
Uterovaginal plexus
Pudendal nerve through pudendal canal (Alcock’s canal)
G-Spot;
G-Spot area of increased sensitivity and erotic pleasure located on front vaginal wall, trigger sexual arousal.
Vaginal Secretion
PH of vagina; 4-5
Acidic, presence of Doderlein’s bacilli, produce lactic acid from glycogen present in exfoliated cells.
Veins
Drain into;
Internal iliac veins
Internal pudendal veins
Lymphatics
In each side lymphatics drain to;
Superficial and deep inguinal nodes.
External iliac lymph node
Internal iliac lymph node
Hymen
The piece of tissue located at opening of vagina hymen needs to be open to allow menstrual blood and normal secretions to exit vagina.
