Vulva(External Genitalia,Pudendum)

 

Development

 

Starts at 8th. Week gestation and completed by 12th. Week.

 

*Genital tubercle……clitoris(phallus in male)

 

*Genital swellings….Labia majora(scrotum in male)

 

*Genital folds……….Labia minora(fuse to form roof of penile urthera in male)

 

*urogenital sinus…..vestibule

 

-Bartholin’s gland and skene tubules develop as outgrowth of urogenital sinus

 

 

 

 

 

 

 

Anatomy

It consists of :

1-Mons Veneris

2-Labia majora

3-Labia minora

4-Clitoris

5-urogenital vestibule and its glands

6-Urtheral meatus and vaginal interiotus

 

 

Mons Venris

 

A pad of fat lying over the syphymsis pubis. The triangular-area that it forms is covered by hair at puberty

 

Labia Majora

 

*Make the lateral boundaries of vulva

*Each is limited externally by genitocrural fold and corresponds to the side of scrotum

*The vestibular cleft between these labia corresponds to the scrotal raphe.

*Round ligament, passing through the inguinal canal of each side, terminates in the upper part of the labium majus of that side

*Canal of Nuck: sometimes a distinict canal remains around the round ligament and form a cystic swelling at the upper part of labium majus

*Coarse hair develop on its outer surface but its inner surface is nonhairy.

*Sebaceous and sweet glands are numerous.

Labia Minora (nymph)

*Two delicate mucocutaneous folds lying on the sides of the vaginal opening

*It begins just below the anterior junction of the labia majora as double folds which pass above and below the clitoris

*The folds join above the clitoris for the prepuce

*On each side labia minora descend along the inner side of labia majora and blend to it near the junction of middle and lower thirds

*the posterior extremities of both labia minora is connected by delicate fold within the posterior margin of vulva, called the Fourchette. When the two labia separated the Fourchette become tense and a depression seen between it and the hymen, called fossa navicularis. This Fourchette is torn at parturition.

*labia minora is rich in blood vessels and lymphatics and act as an erectile tissue.

 

Clitoris

*It is the analogue of penis

*At the symphysis pubis its lower lateral halves separate to form crura

*Rich in blood supply and during sexual stimulation it fills with blood becoming larg and firm

 

Urogenital Vestibule

*it is fissure like when labia is closed and shallow triangle-shaped when separated

*Inferiorly and posterioly the vaginal orfice open

*Superiorly and anteriorly the urethral meatus opens

*Openeings of the major and minor vestibular glands and paraurethral ducts empty in the vestibule.

 

Bartholin’s Gland

The two major vestibular glands correspond to cowper’s glands in male.

*Lie behined the urogenital diaphragm, each gland is close to the lower end of the vestibular bulb of that side(posteriolateral part of vagina)

*the gland is reddish body, the size of a small pea and is a racemose gland

*it produces mucoid secretion that serves as a minor lubricant for coitus

*The opening of the duct from each gland is external to the hymen at about the junction of the lower and middle thirds of the vaginal orfice.

*Normally glands are not palpable, unless infected. Infection is usually non-specific, but may be gonorrheal, and in severe cases abscess forms

*Cyst of gland or duct result from infection or trauma and are frequently seen.

*Malignant neoplasm(rare) may be sq.cell,ductal or adenocarcinoma

 

-Minor vestibular glands are numerous, minute, tube-like depressions frequently seen about the uretheral meatus,between it and the clitoris. They are homologous to the glands of Littre and rarely may be the site of infection

 

 

Urethral Meatus

*Open into the vestibule, covered with stratified sq. epith. With the distal urethra

*Two tubular glands present on the posterior surface of the urethral meatus (Skene ‘s glands.1880)

 

Hymen

*Circular fold of mucosa that partially occlude the vaginal orfice

*It varies in thickness, elasticity and vascularity and also  varies in the number of the openings in it

*Sometimes there is imporforate hymen that prevents escape of the menstrual flow leading to primary amenorrhoea (Cryptomenorrhoea) with cyclic pain. Accumulation of blood leads to hematocolpose, hematometria,hemosalpinx andhemoperitoneum

*Sometimes small openings result in a cribriform pattern

*It usually rupture at the first sexual intercourse,but in some cases it is stretchable and in other cases it is rigid and prevent coitus

*Carunculae Myrtiforms are irregular tages of tissue surrounding the vaginal orifice that result from parturition

 

 

Blood Supply

Internal pudendal arteries which are terminal branches of the anterior division of internal iliac artery

 

Lymphatic Drainage

Lymphatic drains into the superficial and deep inguinal nodes and later to iliac nodes. Sometimes  lymphatic dicussation with drainage into contralateral inguinal nodes occurs.

Drainage of clitoris is into the inguinal and external iliac nodes on both sides

 

Change of Vulva with Age

  • In childhood labia majora are very small and the labia minora project between then
  • As puberty  approaches, the external labia become larger and meet in midian line
  • At puberty it become covered with hair in common with mons veneris
  • A little later in life particularly in married women, the labia minora become enlarged so much that projects forward separating the labia majora
  • In old age labia undergo diminution in size and prominence (Shrinkage being due largely to absorption of fat)

 

 

Vulvar Varicosities

Veins are numerous and large and become much distended when there is intrapelvic pressure as pregnancy or as a result of a tumor. Under these circumstances a wound of the labium may lead to serious and even fatal bleeding.

Anomalies of External Genitalia

 

1-Aplasia

May present with or without normally developed hind limbs

*Severe agensis result in obliteration of perineum with absence of genital, urinary or anal orifices and fusion of lower limbs into one extremity (sirenomelia which is incompatible with life)

 

*With presence of two lower limbs absent genitalia is noted by smooth perineum without orifices. Usually associated with extensive internal developmental defects.

2-Fusion

Agglutination of the labia present from dense adhesions that hold the labia minora and labia majora together in the midline. This probably result from postnatal inflammation which is unnoticed.

Occasionally fusion is complete as to simulate the median raphe of  male perineum and result in disposal of urinary stream.

This is treated by separation of the adhesions and application of surface ointment to prevent recurrence.

 

 

3-Imperforate Hymen (Cryptomenorrhoea)

 The vaginal plate develops near the junction of the lower part of the vagina and the vestibule. Canalization of this plate is generally completed by the 6th. Month of fetal life. Failure of the final process of canalization occurs and result in imperforate hymen which obstruct the menstrual flow.

 

Usually present with primary amenorrhoea with monthly pain, sometimes retention of urine occurs due to blood collected in the vagina(hematocolpos),uterus(hematometria) and tubes(hemosalpinix).