Anatomy of the female Pelvic Organs

 External Genitalia

(Synonym, Vulva, pudendum)

The Vulva includes mons veneris, labia majora, labia minora, citrus, vestibule and conventionally the perineum. These are all visible on external examination. It is therefore bounded anteriorly by the mons veneris, laterally by the labia majora and posterior by the perineum.

Mons Veneris (Mons pubis)

It  is the pas of subcutaneous adipose connective tissue lying in front of the pubis and in the adult female, is covered by hair.

 

Labia Majora

The vulva is bounded on each side by the elevation of skin and subcutaneous tissue which form the labia majora. They are continuous where they join medically to form the posterior composure in front of the anus. The inner surface of labia majora are hairless. The labia majora are covered with squamous epithelium and contain sebaceous glands, sweat glands and hair follicles. Beneath the skin they are dense connective tissue and adipose tissue. The adipose tissue is richly supplied with venous plexus which may produce haematoma, if injured during childbirth. The labia majora are homologous with the scrotum in the Male. The round ligaments terminate at its anterior third.

Labia Minora

Labia minors are two thick folds of skin, devoid of fat, on either side just within the labia majora. Except in the Paris women, they are only exposed when labia majora are separated. Anteriorly, they are divided to enclose the clitoris and unite with each other in front and behind the clitoristo form the produce and frenulum respectively.

   

The lower portion of the labia minora fuses across the midline to form a fold of skin known as fourchette.

It is usually injured during childbirth. Between the fourchette and vaginal orifice is the fossa navicularis. The labia minora do not contain hair follicle. The folds contain connective tissues, numerous sebaceous glands, erectile muscle fibers, and numerous vessels and nerve endings. It is homologous with the ventral aspect of the penis.

Clitoris

Clitoris is a small cylindrical erectile body, measuring about 2.5 cm suited in the most anterior part of the vulva. It consist of glans, a body and two crura. The glans is covered by squamous epithelium and is richly supplied by nerves. The vessels of clitoris are connected with the  vestibular bulb are liable during childbirth.

Clitoris is an analogue to penis in Male, but it differs basically in being entirely separate from the urethra. It is attached to the under surface of the symphysis pubis by the suspensory ligament.

Vestibule

Vestibule is a triangular space bounded anteriorly

by the clitoris, posteriorly by the fourchette and on

either side by labium minus. There are four open-

ings into the vestibule

URETHRAL OPENING

The opening is situated in the midline, just in front

of the vaginal orifice about 1-1.5 cm below the pubic

arch. The paraurethral ducts open either on the posterior wall of the urethral orifice or directly into the vestibule.

Vaginal orifice and hymen

The vaginal orifice lies in the posterior end of the

vestibule and is of varying size and shape. In virgins

and nulliparae, the opening is closed by the labia

minora but in parous, it may be exposed. It is incompletely closed by a septum of mucous 

membrane, called hymen. 

The membrane varies in

shape but is usually circular or crescentic in virgins. The hymen is usually ruptured at the consummation of marriage. During childbirth, the hymen is

The hymen is usually ruptured at the consummation

extremely lacerated and is later represented by

cicatrised nodules of varying sizes, called the

carunculae myrtiformes. On both sides, it is lined

by stratified squamous epithelium.

Opening of Bartholin's ducts

The Bartholin's glands are situated in the super-

ficial perineal pouch, close to the posterior end

of the vestibular bulb. They are pea sized, of

about 0.5 cm and yellowish white in colour During

sexual excitement, it secretes abundant alkaline

mucus which helps in lubrication. Contraction of

bulbocavernosus helps to squeeze the secretion.

The glands are compound racemose variety and

are lined by columnar epithelium. Each gland

has got a duct which measures about 2 cm and

opens into the vestibule outside the hymen at the

junction of the anterior two-third and posterior one-

third in the groove between the hymen and the

labium minus. The duct is lined by columnar

epithelium but near its opening by stratified squamous. The Bartholin's gland corresponds to the bulbourethral gland of Male.

Vestibular Bulb

These are bilateral elongated masses of erectile tissues situated beneath the mucous membrane of the vestibule. Each bulb lies on either side of the vaginal orifice. Infront of the Bartholin's gland and is incorporated within the bulbocavernosus muscles.

They are homologous to the single bulb of penis and corpse spongiosum in the Male.

They are likely to be injured during childbirth with brisk haemorrhage.

Perineum

Blood supply of the vulva

Arteries:

(A) Branches of internal pudendal artery- the chief being labial, transverse perineal, artery to the vestibular bulb and deep and dorsal arteries to the clitoris.

(B) Branches of femoral artery- superficial and deep pudendal.

Veins: 

The veins form plexuses and drain into-

(A) internal pudendal vein,

(B) vesical or vaginal venous plexus

(C) long saphenous vein.

Varicosities during pregnancy are not uncommon and may rupture spontaneously causing visible bleeding or haematoma formation.

Nerve supply of the vulva

The supply is through bilateral spinal somatic nerves. Anterosuperior part is supplied by the cutaneous branches from the ilioinguinal and genital branch of genitofemoral nerve (L1 and L2) and the Posteroinferior part by the pudendal branches from the posterior cutaneous nerve of thigh (S2,3,4).

Between these two groups, the vulva is supplied by the labial and perineal branches of the pudendal nerve (S2,3,4).

In this detailed exploration of the female external genitalia, we have covered the anatomical structures, functions, and common conditions associated with this important part of female anatomy. Understanding the complexities and functions of the external genitalia is crucial for both medical professionals and individuals seeking to enhance their knowledge of female health.  providing a comprehensive guide to the female external genitalia. Thank you for reading, and we hope this information proves valuable in your studies or practice.