Transcript No. 13

No. 13
1. Female Genital System
2. Perineum
Section 2 The Female Genital
Organs




The female genital organs include the internal
genital organs and the external genital organs.
The internal genital organs lie in the pelvic cavity,
and consist of:
① the gonads (the ovaries): produce the ova and
secrete the female hormones.
② the reproductive canals or conveying ducts
(uterine tubes, uterus and vagina).
③ the accessory glands: greater vestibular glands
(Bartholin’s glands). They are the homologous
organs of the bulbourethral glands in the male.




The matured follicle ruptures on the surface of
the ovary and the ovum is discharged into the
peritoneal cavity, then the uterine tube. If the
ovum is fertilized in the uterine tube, it is carried
to the uterus and develops within the
endometrium.
The mature fetus passes through the ostium of
the uterus, vagina during childbirth.
If fertilization does not occur, the ovum begins
degeneration after a short time.
The female external genital organs is called the
female pudendum collectively.
Ⅰ. The Internal Genital Organs
Ⅰ) The Ovaries
 They are a pair of oval organs,
homologus with the testes in the
male. The ovaries are female gonads,
producing female reproductive cells—
the ova and secrete the female
hormones.
1. Location:
 They are situated one on each side
of the uterus close to the lateral wall
of the lesser pelvis, in the ovarian
fossa, between the upper parts of
the internal iliac artery and external
iliac artery.


2. External features:
Each ovary has:
1) Lateral and medial surfaces: The medial
surface is close to the loops of small intestine.
2) Anterior and posterior borders: The posterior
border is free, and the anterior border is attached
to the posterior surface of the broad ligament by
the mesovarium. At the middle part of the
anterior border there is the hilum of ovary,
through which the blood vessels and nerves pass.


3) Surperior and inferior extremities: The
superior extremity, the tubal extremity,
connectes with the fimbria of uterine tube.
The inferior extremity, the uterine
extremity, connects with fundus of uterus.
In childhood, the ovaries are small with
smooth surfaces. After puberty the ovary
becomes progressively scarred, because of
the ovulations. After the ages of 40～50,
the ovaries become atrophy gradually as
the menstruation has ceased.
3. The supporting structures of ovaries
 The ovaries are maintained in position by a series
of ligaments:
 1) The suspensory ligament of ovary, or
infundibulopelvic ligament, extends from its
superior extremity to the pelvic wall, which
contains the ovarian vessels, lymphatic vessels,
nerves and connective tissues.
 2) The proper ligament of ovary passes from
the inferior extremity to the fundus of uterus. It
is a rounded cord of connective tissue.
Ⅱ) The Uterine Tubes

They are two tortuous muscular
tubes which transmit the ovum. It is
10～14 cm long, 0.5 cm in diameter.
1. Location:



They are situated on the upper margins of
the broad ligaments of the uterus, and run
from each side of the fundus of uterus to
the wall of the pelvis.
Just before reaching the pelvic wall they
turn back upon themselves to open into
the peritoneal cavity through the
abdominal orifice.
Its medial end opens into the superior
angle of the cavity of uterus through the
uterine orifice.
2. Divisions and their significance:





The uterine tube is divided into four
parts:
the uterine part,
the isthmus of uterine tube,
the ampulla of uterine tube,
the infundibulum of uterine tube,



1) The uterine part (or intramural part)
It lies in the wall of the uterus, about 1 cm long.
2) The isthmus of uterine tube
It is the medial and narrow portion of the tube,
about 2.5 cm long.
It is the place where the tubal ligation is
performed usually.
3) The ampulla of uterine tube
It is the longest and widest part of the tube,
between the infundibulum and the isthmus. It
forms about 2/3 of the entire length of the tube.
It is the side of fertilization.



4) The infundibulum of uterine tube
It is a funnel-shaped lateral end of the
uterine tube around the ovary superiorly
and posteromedially. It is fringed with
numerous processes, fimbriae, which
spread over most of the medial surface of
the ovary.
One of them attaching to the superior
extremity of the ovary is called the
ovarian fimbria.


When an ovum is discharged from the
ovary, it may be caught by the fimbrae
and passes through the abdominal orifice
of the tube. Sperm reach the infundibulum
within hours after entering the cervix, and
fertilization usually occurs in the ampulla.
On occasion, a fertilized ovum fails to pass
into the uterus and begins to develop in
the uterine tube (usually the ampulla), or
becomes implanted in the pelvic cavity.
Both pelvic and tubular implantations are
referred to as ectopic pregnancies.
Ⅲ) The Uterus

It is a single, hollow organ, with
thick muscular wall, in which the
fertilized ovum becomes embedded
and the developing organism grows
until its birth.
1. The features of the uterus




In the adults, the uterus is shaped like an
inverted pear, and flattened
anteroposterioly.
In the young nulliparous adult, it
measures 7～8 cm long, 4 cm wide at its
superior end, and 2～3 cm in thickness.
It has the anterior and posterior surfaces,
right and left borders.
The anterior surface is related to the
urinary bladder, and posterior surface to
the rectum.
(1) Divisions of the uterus
 The uterus consists of three portions:
cervix, body and fundus.
① Fundus
 The fundus is the superior domeshaped portion above the uterine
orifice of the uterine tube.
② Cervix
 The inferior portion is narrow, and opens
into the vagina, called the cervix.
 The cervix of uterus is 2.5～3.0 cm long.
 Its inferior 1/3 is surrounded by the
superior portion of the vagina, so called
the vaginal part.
 The superior 2/3 is called the
supravaginal part.


The cavity of cervix is called the cervical
canal of uterus. The lower end of the
cervical canal has the round opening,
called the orifice of uterus which is
smooth and round in nullipara, and in the
multipara it is a transverse fissure.
The anterior border of the orifice of uterus
is called the anterior lip and the posterior
border the posterior lip, which is longer
and higher than the anterior lip.



Isthmus:
Between the body and the cervix is a
constricted region about 1 cm in length,
the isthmus. During pregnancy the
isthmus enlarges greatly and is taken up
by the body, it is therefore often referred
to by obstricians as the “lower uterine
segment”. The caesarean section is usually
performed at here.
③ Body
Between the cervix and the fundus is the
body.
(2) The interior cavity of uterus
 The interior cavity of the uterus is
narrow during nonpregnancy.
It is divided into two parts:
① The cavity of uterus
 It is the superior part, the cavity of
uterus, within the body of uterus, is
triangular in coronal section with the
base upwards.
 Its upper two angles communicate
with the uterine tubes by the uterine
orifice of the uterine tube.
② The cervical canal of uterus
 The inferior part within the cervix is
called the cervical canal of uterus,
which is spindle-shaped and
communicates above, through the
internal ostium, with the cavity of
the body, and below, through the
orifice of uterus, with the vaginal
cavity.
2. The location of uterus




Normally, the uterus is located
entirely in the lesser pelvis between
the urinary bladder and the rectum.
Its inferior end lies in the vagina.
There are uterine tube, ovary and
broad ligament on its two sides.
The fundus of the uterus is below the
level of the pelvic inlet, and the
inferior end above the ischial spine.


Anteversion and anteflexion:
When the bladder is empty the entire
uterus is inclined forward upon the bladder,
forming an angle (about 90o) between the
long axis of the uterus and the vagina,
called the anteversion.
And also the long axis of the body of the
uterus is bent forward on the long axis of
the cervix forming an angle of about 170o,
which is called the anteflexion.


As the bladder fills, the uterus
gradually becomes more and more
erect.
The uterus varies in shape, size,
location and structure, depending
upon age and other circumstances,
such as pregnancy etc.

The peritoneum which covers the posterior
part of surface of uterus runs down to the
posterior part of fornix of vagina, then it
reflects onto the rectum, forming the
rectouterine pouch. But the peritoneum on
the anterior surface of the uterus reflects
onto the superior surface of the urinary
bladder at the junction of the body and
the neck of uterus, forming the
vesicouterine pouch.
3. The supports of uterus

The normal position of the uterus is
maintained by various ligaments and
other supports such as the muscles
of pelvic floor, neighbouring organs
and connective tissue. Damage to
these structures may result
downward displacement of uterus,
called prolapse.



(1) The broad ligaments
The broad ligaments are composed of two layers
of peritoneum, from the lateral margin of the
uterus to the lateral wall and floor of the pelvis.
The free superior edge of the broad ligament
contains the uterine tube. The inferior and lateral
margins continue with the peritoneum on the wall
of pelvis.
In the broad ligament there are the uterine tube,
ovary, proper ligament of ovary, round ligament
of uterus, blood vessels, lymphatic vessels,
nerves and connective tissue.
The portions of the broad ligament:
 The broad ligament is divided into
three portions, the mesovarium
extending from the anterior border of
the ovary to the posterior layer of
the broad ligament, the
mesosalpinx between the uterine
tube and the mesovarium and
mesometrium.



(2) The round ligaments of uterus
The round ligaments of uterus are two bands of
fibromuscular tissue between the layers of the
broad ligament.
Each one attaches to the uterus just below and in
front of the uterine orifice of the uterine tube and
runs anterolaterally to the lateral wall of the
pelvis, then traverses the inguinal canal, ends in
the subcutaneous tissue of the greater lip of
pudendum.
The round ligament tends to hold the uterus in
the anteverted position.
(3) The cardinal ligaments
 The cardinal ligaments extend below the
base of the broad ligaments between the
pelvic wall and the cervix of uterus.
 These ligaments contain fibrous tissue,
smooth muscle, uterine blood vessels,
nerves and are the chief ligaments
supporting the position of the uterus to
prevent from dropping down into the
vagina.


(4) The uterosacral ligaments
The uterosacral ligaments are also
called the rectouterine ligaments.
They are two folds of peritoneum
containing a considerable amount of
fibrous tissue and smooth muscular
fibers.


The ligaments pass backwards from
each side of the cervix of uterus, the
sides of the rectum, to the front of
the second and third sacral vertebrae.
The ligaments hold the cervix of
uterus in its normal position relative
to the sacrum. The uterosacral
ligament tends to hold the uterus in
the anteflexion position.
4. The structures of uterus




The wall of uterus is made up of three coats.
1) The endometrium, the inner coat is mucous
membrane, which grows and breaks away during
the menstrual cycle.
2) The myometrium, the middle coat is made
up of smooth muscle. It is 0.8 cm thick and
composed of smooth muscle fibers interspersed
with connective tissue and is highly vascular. This
coat thickens to 2.5 cm during pregnancy.
3) The outer serous coat is composed of
visceral peritoneum. This coat covers most of the
uterine surface except for the cervix.
Ⅳ) The Vagina

It serves as a passage for the
menstrual flow and as the female
organ of copulation and the lower
portion of the “birth canal”.


Location:
The vagina is situated between the bladder and
urethra anteriorly and the rectum and anal canal
posteriorly.
It consists of three coats: mucous membrane,
muscular coat and external coat. It is 8-10 cm long,
extending from the cervix of the uterus to the
vaginal vestibule. Its upper portion lies above the
pelvic floor and the lower portion is narrow and
opens to the vaginal vestibule through the vaginal
orifice, which is protected in the virgin by a thin
mucosal fold called the hymen, which is perforated
at its center. Where it passes through the
urogenital diaphragm, the urethrovaginal sphincter
encircles it.



Fornix of vagina:
The upper end of vagina surrounds the
vaginal portion of the cervix of uterus to
form a circular recess, called the fornix of
vagina.
Its posterior part is higher than the
ventral part and two lateral parts.
Between the posterior part and the
rectouterine pouch, an aspiration or a
drainage may be performed through the
posterior part.
Ⅴ. The Greater Vestibular Glands
(Bartholin’s glands)


They are about the size of pea and
situated one on each side of the
vaginal orifice posterior to the bulb of
vestibule, deep to the sphincter of
vagina. Each gland has a duct which
opens between the hymen and the
lesser lip of pudendum.
They are the homologous organs of
the bulbourethral glands in the male.
Ⅱ. The External Genital Organs

The external genital organs of female
are known collectively as the vulva,
or female pudendum, which
comprises:
①the mons pubis,
②the greater lip of pudendum,
③the lesser lip of pudendum,
④the clitoris,
⑤the vaginal vestibule: It is a cleft
between the lesser lips of pudendum,
behind the clitoris.
 It contains the external orifice of urethra
anteriorly, 2.5 cm inferoposterior to the
clitoris, and the vaginal orifice posteriorly.
 On the each side of the vaginal orifice
there is the orifice of greater vestibular
gland.
⑥the hymen.
Ⅲ. The Mammae in Female



Ⅰ) The Location
In the young adult female each mamma
forms a round eminence lying within the
superficial fascia over the pectoralis major
and the deep fascia.
It extends from the third to seventh ribs
vertically, and from the parasternal line to
midaxillary line transversely.
Ⅱ) The Features
 The mammary nipple is on the center of
the mamma and commonly lies at the
level of the fourth intercostal space.
 On the wrinkled tip of the nipple there are
orifices of 15～20 lactiferous ducts. The
base of nipple is encircled by a pigmented
area of skin called the areola of breast.
On its surface there are many small
eminences of areolar glands, which
secrete oily secretion to lubricate the
nipple.



Ⅲ) The Structure
The mamma is composed of the
mammary gland and adipose tissue mainly.
Each mammary gland consists of fifteen to
twenty lobes, separated by the adipose
tissue, which radiate out from the nipple.
Each lobe has an excretory duct, the
lactiferous duct, which is enlarged near
the nipple called the lactiferous sinus, the
end of which is narrowed and opens on
the nipple.



The incision in the operation on mamma should
be made radially to avoid cutting across a
number of the lactiferous ducts.
Between the skin and the deep fascia, deep to
the mammary glands, there are strands of
connective tissue called the suspensory
ligaments of breast or Cooper’s ligaments,
which serve to support the mammary glands.
These ligaments may become contracted by
fibrosis in cancer of the mamma, thus the
overlying skin becomes pitted and retracted.
Thereby, it gives an appearance of orange-peel.
Section 3 The Perineum



The perineum is the diamond-shaped
region of the outlet of the pelvis.
It includes all the soft tissue between the
pubic symphysis and the coccyx.
It surrounded anteriorly by the inferior
border of the pubic symphysis, laterally by
the inferior rami of pubis, rami of ischium,
ischial tuberosities, sacrotuberous
ligaments, posteriorly by the apex of
coccyx.


A transverse line drawn between the
ischial tuberosities divides the perineum
into an anterior urogenital region
(urogenital triangle) that contains the
external genital organs and the urethra,
and a posterior anal region (anal
triangle) that contains the anus.
In the female, the region between the
vagina and anus is known as the
obstetrical perineum, and it is often torn
during childbirth.
Ⅰ. The Anal Region




The anus is in the center of this
triangle. On each side of the anal
canal there is a large space called
the ischioanal fossa (ischorectal
fossa).
Ⅰ) The Sphincter Ani Externus
Ⅱ) The Levator Ani
Ⅲ) The Coccygeus







Ⅳ) The Superior and Inferior Fasciae of Pelvic
Diaphragm
These fasciae cover the levator ani and coccygeus
superiorly and inferiorly.
The levator ani and coccygeus together with the
superior and inferior fascia of pelvic diaphragm
constitute the pelvic diaphragm.
There is a hiatus of pelvic diaphragm anterior to
the perineal central tendon between the levator ani
of each side.
In the male the prostate extends into the hiatus
and the urethra passes through its center.
In the female the urethra and the vagina pass
through this hiatus.
Inferior to hiatus there is the urogenital diaphragm.



Ⅴ) The Ischiorectal Fossa (Ischioanal fossa)
It is a space located between the skin of
the anal region below, the obturator
internus and its fascia, ischial tuberosity
laterally, and the levator ani, sphincter ani
externus, inferior fascia of pelvic diaphragm
medially.
It is filled with adipose tissue and contains
the vessels and nerves.
The internal pudendal artery, vein and the
pudendal nerve pass through this fossa
along its lateral wall from posterior to
anterior to supply the perineum.
Ⅱ. The Urogenital Region


It is the area between the pubic
arches of both sides.
Its apex is directed forward and the
base is backward.
Ⅰ) The Fasciae of Urogenital
Diaphragm


1. The superficial fascia
Its deep layer is called superficial fascia of
perineum (Colles fascia)
2. The inferior fascia of urogenital
diaphragm
3. The superior fascia of urogenital
diaphragm
The three layers form two spaces of fascia
the superficial perineal space is
between the first and second layers, the
deep perineal space is between the
second and third layers.
Ⅱ) The Muscles of Urogenital
Diaphragm
1. The muscles in the superficial
perineal space
 Superficial transverse muscle of
perineum,
 Bulbocavernosus
 Ischiocavernosus.


2. The muscles in the deep perineal space
The deep transverse muscle of
perineum and the sphincter of urethra
(sphincter of the membranous portion of
urethra ) are in the deep perineal space.
The sphincter of urethra is also called the
external sphincter of urethra in male
and the urethrovaginal sphincter in female.

The muscles in the deep perineal
space, the superior and inferior
fasciae of perineum are called the
urogenital diaphragm collectively,
which is superficial to the pelvic
diaphragm and closes the urogenital
triangle.


3. The structures in the superficial
and deep perineal spaces
In the superficial perineal space
besides the nerves and blood vessels
to supply the perineum, there are
the bulb of urethra and the crura of
penis in male, the bulb of vestibule,
crura of clitoris and greater
vestibular glands in female.

In the deep perineal space there are
the blood vessels and nerves
supplying the penis, membranous
part of urethra, bulbourethral glands
in male and the urethra and vagina
in female.