OUTLINE IN OBSTETRICS
CHAPTER 1: ANATOMY AND
PHYSIOLOGY
FEMALE EXTERNAL GENITALIA
The term VULVA or PUNEDA
refers to the entire female external
genitalia.
Mons Pubis/ Mons Veneris –a pad
of fat above the symphisis pubis. The
mons is richly supplied with sebaceous
glands. Hairless nad smooth in
childhood, it is covered by curly hair,
called escutcheon, after puberty. The
hair pattern in female is triangular
with base up and in male, diamond- erectile tissues called corposa
shaped. cavernosa that are connected to the
Labia Majora –are two thick folds of pubic bone. It is supplied with many
adipose tissues originating from the sebaceous glands that produce a
mons and terminating in the cheese-like secretion called smegma.
perineum, its outer surface is thick The clitoris is used as a guide in
and covered by hair and its inner female catheterization. During sexual
aspect is thin, smooth and moist. It arousal, the ischiocavernous muscle
unites anteriorly to form the anterior surrounding it contracts blocking blood
commissure and posteriorly to form flow resulting in clitorial congestion
the posterior commissure. Its main and erection.
function is to provide covering and Fossa Navicularis –it refers to the
protection to the external organs space between the fourchette and
located under it. In nulliparous women vaginal introitus. It is usually
it is in close apposition to each other. obliterated during childbirth.
It tends to gape wider after every Vestibule –is a triangular space
childbirth. located between the labia minora
Labia Minora –are two thin folds of containing the following openings;
connective tissue that joins anteriorly vaginal introitus, urethral meatus,
to form the prepuce and posteriorly to Bartholin’s glands and Skene’s glands.
form the fourchette. The lower border Bartholin’s Glands –also known as
of the upper portion (below prepuce) vulvovaginal gland, paravaginal gland
is called frenulum. It is highly vascular, and major vestibular glands. A pair of
sensitive and richly supplied with glands located at each inner side of
sebaceous glands. In nulliparous the vagina that secretes alkaline
women, the labia minora cover the mucus which helps to keep the vaginal
vaginal introitus, vestibule and introitus lubricated and enhance
urethra. Being very fragile, it is usually sperm survival.
torn during vaginal delivery. Skene’s Glands –also known as
Clitoris –is a highly sensitive and paraurethral and minor vestibular
erectile tissue situated under the glands. A pair of glands situated at
prepuce of the labia minora. It is each inner side of the urethral meatus.
highly sensitive to touch and The secretions of the Skene’s glands
temperature. It is composed of two and Bartholin’s glands increases with
, sexual stimulation to lubricate anterior surrounded by the bulbocavernous
surface of the vagina. muscle.
Vaginal Orifice –the external opening When a woman performs Kegel’s
of the vagina located just below the exercise the tone of this group of
urethral meatus. The Grafenberg or G- muscles is greatly improved.
spot is a very sensitive area located at Functions:
the inner anterior surface of the 1. Organ of copulation
vagina. 2. Discharges menstrual flow
Hymen –is a thin circular membrane 3. Birth canal
made of elastic tissu4e situated at the Rugae –they are transverse folds of
vaginal opening and which is torn skin in the vaginal wall that is absent
during the first sexual intercourse and in childhood, appear after puberty and
childbirth. The hymen separates the disappears at menopause. It is most
female internal organs to the external numerous in nulliparous women and
organs. Imperforate hymen is a hymen lessens with each childbirth and
that is completely covering the vaginal advancing age. Its important function
introitus preventing the passage of is to allow the vaginal canal to stretch
menstrual discharge and sexual and enlarge during delivery.
intercourse. Hymenotomy or Vaginal Column –longitudinal folds of
hymenectomy is the surgical incision skin in the vaginal canal.
of an imperforate hymen. Vaginal Vault –upper end of the
Urethral Meatus –the external vagina.
opening of the female urethra is Fornix/Fornices –the cervix projects
located just below the clitoris, the to the vagina forming four recesses or
shortness of the female urethra makes depression around its upper portion
women more susceptible to urinary called fornices; anterior fornix, lateral
tract infection (UTI) than men. fornices, posterior fornix. The posterior
Blood Supply –blood supply to vulva (10cm) of the vagina is longer than
is provided by the pudendal artery and the anterior wall (7cm). the posterior
inferior rectus artery. This rich blood fornix is the deepest of the fornices, it
supply facilitates rapid healing during is in this area that vaginal secretions
the postpartum period. collect and semen pools.
Nerve supply –the anterior portion Vaginal pH –vaginal pH before
nerve supply is derived from the L1 puberty is 6.8 to 7.2, which is alkaline.
(ilioinguinal and genitofemoral nerve) After puberty vaginal pH goes down to
and the posterior portion is derived 4-5, which is acidic. This is because
from S3 (pudendal nerve). before puberty the young girls do not
have enough estrogen yet to stimulate
THE INTERNAL ORGANS cervical mucus secretion but with the
advent of puberty, her ovary begins to
Vagina –is a hollow, membranous and produce estrogen which stimulates
muscular canal about 8 to 12cm long mucus production in the cervix. This
located in front of the rectum and mucus is rich in glycogen. The
behind the bladder. It is composed of glycogen content of vaginal mucus
connective and elastic tissues, and (which increases after puberty) is
muscle fibers. Its surface is lined by converted to lactic acid by Doderlein
stratified squamous epithelium. Its bacilli (a bacteria normally present in
upper portion is separated from the the vagina) making the vaginal
rectum by the cul-de-sac of Douglas. environment acidic- this helps prevent
The external opening of the vagina is the growth of pathogenic
CHAPTER 1: ANATOMY AND
PHYSIOLOGY
FEMALE EXTERNAL GENITALIA
The term VULVA or PUNEDA
refers to the entire female external
genitalia.
Mons Pubis/ Mons Veneris –a pad
of fat above the symphisis pubis. The
mons is richly supplied with sebaceous
glands. Hairless nad smooth in
childhood, it is covered by curly hair,
called escutcheon, after puberty. The
hair pattern in female is triangular
with base up and in male, diamond- erectile tissues called corposa
shaped. cavernosa that are connected to the
Labia Majora –are two thick folds of pubic bone. It is supplied with many
adipose tissues originating from the sebaceous glands that produce a
mons and terminating in the cheese-like secretion called smegma.
perineum, its outer surface is thick The clitoris is used as a guide in
and covered by hair and its inner female catheterization. During sexual
aspect is thin, smooth and moist. It arousal, the ischiocavernous muscle
unites anteriorly to form the anterior surrounding it contracts blocking blood
commissure and posteriorly to form flow resulting in clitorial congestion
the posterior commissure. Its main and erection.
function is to provide covering and Fossa Navicularis –it refers to the
protection to the external organs space between the fourchette and
located under it. In nulliparous women vaginal introitus. It is usually
it is in close apposition to each other. obliterated during childbirth.
It tends to gape wider after every Vestibule –is a triangular space
childbirth. located between the labia minora
Labia Minora –are two thin folds of containing the following openings;
connective tissue that joins anteriorly vaginal introitus, urethral meatus,
to form the prepuce and posteriorly to Bartholin’s glands and Skene’s glands.
form the fourchette. The lower border Bartholin’s Glands –also known as
of the upper portion (below prepuce) vulvovaginal gland, paravaginal gland
is called frenulum. It is highly vascular, and major vestibular glands. A pair of
sensitive and richly supplied with glands located at each inner side of
sebaceous glands. In nulliparous the vagina that secretes alkaline
women, the labia minora cover the mucus which helps to keep the vaginal
vaginal introitus, vestibule and introitus lubricated and enhance
urethra. Being very fragile, it is usually sperm survival.
torn during vaginal delivery. Skene’s Glands –also known as
Clitoris –is a highly sensitive and paraurethral and minor vestibular
erectile tissue situated under the glands. A pair of glands situated at
prepuce of the labia minora. It is each inner side of the urethral meatus.
highly sensitive to touch and The secretions of the Skene’s glands
temperature. It is composed of two and Bartholin’s glands increases with
, sexual stimulation to lubricate anterior surrounded by the bulbocavernous
surface of the vagina. muscle.
Vaginal Orifice –the external opening When a woman performs Kegel’s
of the vagina located just below the exercise the tone of this group of
urethral meatus. The Grafenberg or G- muscles is greatly improved.
spot is a very sensitive area located at Functions:
the inner anterior surface of the 1. Organ of copulation
vagina. 2. Discharges menstrual flow
Hymen –is a thin circular membrane 3. Birth canal
made of elastic tissu4e situated at the Rugae –they are transverse folds of
vaginal opening and which is torn skin in the vaginal wall that is absent
during the first sexual intercourse and in childhood, appear after puberty and
childbirth. The hymen separates the disappears at menopause. It is most
female internal organs to the external numerous in nulliparous women and
organs. Imperforate hymen is a hymen lessens with each childbirth and
that is completely covering the vaginal advancing age. Its important function
introitus preventing the passage of is to allow the vaginal canal to stretch
menstrual discharge and sexual and enlarge during delivery.
intercourse. Hymenotomy or Vaginal Column –longitudinal folds of
hymenectomy is the surgical incision skin in the vaginal canal.
of an imperforate hymen. Vaginal Vault –upper end of the
Urethral Meatus –the external vagina.
opening of the female urethra is Fornix/Fornices –the cervix projects
located just below the clitoris, the to the vagina forming four recesses or
shortness of the female urethra makes depression around its upper portion
women more susceptible to urinary called fornices; anterior fornix, lateral
tract infection (UTI) than men. fornices, posterior fornix. The posterior
Blood Supply –blood supply to vulva (10cm) of the vagina is longer than
is provided by the pudendal artery and the anterior wall (7cm). the posterior
inferior rectus artery. This rich blood fornix is the deepest of the fornices, it
supply facilitates rapid healing during is in this area that vaginal secretions
the postpartum period. collect and semen pools.
Nerve supply –the anterior portion Vaginal pH –vaginal pH before
nerve supply is derived from the L1 puberty is 6.8 to 7.2, which is alkaline.
(ilioinguinal and genitofemoral nerve) After puberty vaginal pH goes down to
and the posterior portion is derived 4-5, which is acidic. This is because
from S3 (pudendal nerve). before puberty the young girls do not
have enough estrogen yet to stimulate
THE INTERNAL ORGANS cervical mucus secretion but with the
advent of puberty, her ovary begins to
Vagina –is a hollow, membranous and produce estrogen which stimulates
muscular canal about 8 to 12cm long mucus production in the cervix. This
located in front of the rectum and mucus is rich in glycogen. The
behind the bladder. It is composed of glycogen content of vaginal mucus
connective and elastic tissues, and (which increases after puberty) is
muscle fibers. Its surface is lined by converted to lactic acid by Doderlein
stratified squamous epithelium. Its bacilli (a bacteria normally present in
upper portion is separated from the the vagina) making the vaginal
rectum by the cul-de-sac of Douglas. environment acidic- this helps prevent
The external opening of the vagina is the growth of pathogenic
