EXTERNAL GENITALIA/
VULVA

Introduction
• The reproductive organ in female are those which concerned with copulation,
fertilization, growth and development of fetus and its subsequent exit to the outer
world.
• The female reproductive organs can be subdivided into
• a) External genitalia
• b) Internal genitalia
• c) Accessory reproductive organs.

Functions of female reproductive system
• The female reproductive system is designed to carry out several functions.
It produces the female egg cells necessary for reproduction, called the ova
or oocytes. The system is designed to transport the ova to the site of
fertilization.
• Fertilization of an egg by a sperm, normally occurs in the fallopian tubes.
The next step for the fertilized egg is to implant into the walls of the uterus,
beginning the initial stages of pregnancy.
• If fertilization and/or implantation does not take place, the system is
designed to menstruate .
• In addition, the female reproductive system produces female sex
hormones that maintain the reproductive cycle.

External genitalia or vulva
• Parts that are outwardly visible are called vulva. Externat genitalia is also
known as pudendum.
• The vulva includes:
• Mons pubis
• Labia majora
• Labia minora
• Clitoris
• Vestibule
• Urethral opening
• Vaginal opening
• Greater vestibular glands/ Bartholin glands
• Perineum
There are individual differences in
• Size
• Coloration
• Shape

UNIT 3: FEMALE REPRODUCTIVE SYSTEM 5

Functions of vulva
• The vulva (pudendum) refers to the external female genitalia.
Its functions are:
• Assists in micturition by directing the flow of urine
• Protects the internal female reproductive tract from infection.
• Acts as sensory tissue during sexual intercourse

Structures of the Vulva
Vulva is a collective term for several anatomical structures:
• Mons pubis
• Labia majora
• Labia minora
• Clitoris
• Vestibule
• Bartholin’s glands /
• Perineum

Mons pubis
• The rounded pad of subcutaneous fat located anterior to the
pubic symphysis.
• It protects the pubic symphysis.
• During adolescence sex hormones trigger the growth of pubic hair on the
mons pubis
• Hair varies in coarseness curliness, amount, color and thickness

Labia majora
• Labia majora are two hair-bearing thick fold of skin, fibrous tissues and fat.
They are also referred as outer lips of vulva. They form the lateral boundaries of
pudendal cleft.
• Their outer surfaces are covered with hair, the inner surfaces have large sebaceous
glands
• Anteriorly the folds join in front of the symphysis pubis to each other below the
mons pubis to form the anterior commissure.
• Posterior ends of the labia are less prominent and merge with the skin, known as
the posterior commissure.
• The area between posterior commissure and the anus which is about 2.5 cm
constitutes perineum.

Labia minora
• Labia minora are two hairless folds of skin, which lie within the labia
majora.
• They fuse anteriorly to form the hood of the clitoris and extend posteriorly
either side of the vaginal opening.
• Anteriorly, each labium minora splits into two layers, the upper layer joins
the corresponding layer of the opposite side, to form the prepuce / hood of
the clitoris. Similarly, the lower layers of the two sides join to form
frenulum of the clitoris.
• Posteriorly, the two labia minora merge posteriorly, creating a fold of skin
known as the fourchette.
• The inner surface of the labia minora contains numerous sebaceous glands.

Clitoris
• Highly sensitive organ composed of nerves, blood vessels, and
erectile tissue.
• It is formed of erectile corpora cavernosa tissue, which becomes
engorged with blood during sexual stimulation. It plays a role in
sexual pleasure for most women, but has no reproductive
significance.
• It is homologous to penis in males.

Vestibule
• The cleft between the labia minora is known as vestibule. Urethra,
vagina, and ducts of the greater vestibular glands open into the vestibule.
• Urethral orifice lies most anteriorly about 2.5 cm below the clitoris and
in front of the vaginal orifice.
• Vaginal orifice or introitus lies in the posterior part of the vestibule and is
partly closed in the virgin by a thin membrane called the hymen.
• Openings of the ducts of greater vestibular glands lie one on each side of
vaginal orifice.

Bartholin’s glands / greater vestibular glands
• The greater vestibular glands (Bartholin’s glands) are pea sized
glands, situated one on each side near the vaginal opening. They
are about the size of a small pea and have ducts, opening into the
vestibule immediately lateral to the attachment of the hymen and
labia minora.
• These glands secrete mucus that keeps the vulva moist.

Perineum
• It is roughly triangular area located between the vaginal opening and
anal opening.
• It consists of connective tissue, muscles and fat.
• It gives attachment to the muscles of the pelvic floor.
• It supports and surrounds the lower parts of the urinary and digestive
tracts.
• The perinium also contain an abundance of nerve endings that
make it sensitive to touch.
• An episiotomy is an incision of the perinium used during childbirth for
widening the vaginal opening.

Blood supply, lymph drainage and nerve supply
• Arterial supply
This is by branches from the internal pudendal arteries that branch from the
internal iliac arteries and by external pudendal arteries that branch from the
femoral arteries.
• Venous drainage
This forms a large plexus which eventually drains into the internal iliac veins.
• Lymph drainage
This is through the superficial inguinal nodes.
• Nerve supply
This is by branches from pudendal nerves.

Vagina
Vagina is a fibromuscular canal / tube that connects external and internal genitalia of
the female. It runs obliquely upwards and backwards from vaginal orifice to cervix at
an angle of about 45° between the bladder in front and rectum and anus behind.
Direction: In the erect posture, the vagina is directed upwards and backwards. Long
axis of uterus and cervix forms an angle of 90° with long axis of vagina.
Relationship:
• The vagina is closely related to many of the organs in the pelvic region:
• Anterior - bladder and urethra.
• Posterior – rectouterine pouch, rectum and anal canal.
• Lateral – ureters and levator ani muscle.

Contd…
Size and shape:
The anterior wall of the vagina is about 7.5 cm long and the posterior wall about 9 cm
long. The difference is due to the angle of insertion of the cervix through the anterior wall.
The diameter of the vagina gradually increases from below upwards. The upper end or
vault is roughly 5 cm, twice the size of the lower end (2.5 cm).
In the virgins, the lower end of the vagina is partially closed by a thin annular fold of
mucous membrane called the hymen. In married women, the hymen is torn and
represented by rounded elevations around the vaginal orifice, the caruncular hymenales.
The shape of the vagina is not a round tunnel. In the transverse plane it is more
like an “H” lying on the side. Because anterior and posterior walls – these are
normally collapsed and thus in contact with one another.

Standing and lying down posture

Contd…
Fornices of vagina:
The interior of the upper end of the vagina or vaginal vault is in the form
of a circular groove that surrounds the protruding cervix. The groove is
divided into four parts called the vaginal fornices. The anterior fornix lies
in front of the cervix and is the shallowest. The posterior fornix lies
behind the cervix and is the deepest. Lateral fornices are one on each side
of cervix.
Posterior fornix is important as it acts like a natural reservoir for semen
after intravaginal ejaculation. The semen retained in the fornix liquefies
in the next 20-30 mins, allowing for easier permeation through the
cervical canal.

Histology of the Vagina
Vagina is composed of four histological layers (internal to external):
• Stratified squamous epithelium- innermost layer, this layer provides
protection and is lubricated by cervical mucus from Bartholin glands(the
vagina itself does not contain any glands).
• Elastic lamina propria - a dense connective tissue layer which projects
papillae into the overlying epithelium. The larger veins are located here.
• Fibromuscular layer - comprising two layers of smooth muscle, an inner
circular and an outer longitudinal layer.
• Adventitia - a fibrous layer, which provides additional strength to the
vagina whilst also binding it to surrounding structures.

Vascular Supply and Lymphatics
• Arterial supply: The arterial supply to the vagina is via the uterine and
vaginal arteries – both branches of the internal iliac artery.
• Venous drainage: Venous return is by the vaginal venous plexus,
which drains into the internal iliac veins via the uterine vein.
• Lymphatic drainage: Lymphatic drainage is divided into three sections:
Superior – drains to external iliac nodes
Middle – drains to internal iliac nodes
Inferior – drains to superficial inguinal lymph nodes.22)

Nerve supply
• Nerve Supply --The lower one-third of the vagina is pain sensitive
and is supplied by deep perineal nerve, a branch of the pudendal
nerve. The upper two-thirds of the vagina are pain insensitive and are
supplied by sympathetic L1, 2 and parasympathetic segments S2 to
S4.

Functions of vagina
• Sexual intercourse – receives the penis and ejaculate, assisting in
its transport of sperm to the uterus.
• Childbirth – expands to provide a channel for delivery of a
newborn from the uterus.
• Menstruation – serves as a passage / canal for menstrual fluid
and tissues to leave the body.