2. Introduction
Synonym: Latin uterus; Greek hystera: womb
The uterus is a childbearing organ in females.
It provides a suitable site and environment for
implantation of a fertilized ovum and
development of the embryo.
The uterus is a thick-walled, muscular organ
with narrow lumen.
Situated in the pelvis between the urinary
bladder and the rectum.
Superiorly, on each side, it communicates with
the uterine tube and inferiorly with the vagina.
Dr.Vibhash
3. Shape and Size
It is pear-shaped, being flattened
anteroposteriorly.
Measurements:
Length: 3 inches (7.5 cm).
Breadth (at fundus): 2 inches (5 cm).
Thickness: 1 inch (2.5 cm).
Weight: 30–40 g.
Dr.Vibhash
4. SUBDIVISIONS/PARTS OF THE UTERUS
The uterus is divided into two main parts:
(a) the large upper pear-shaped part—the body.
(b) a small lower cylindrical part—the cervix.
The body forms upper 2/3rd of uterus and cervix
forms the lower 1/3rd of the uterus.
The junction between the body and cervix is
marked by a circular constriction called isthmus.
The uterine tubes are attached to the upper part of
the body.
The point of fusion between the uterine tube and
body is called cornu of the uterus.
Dr.Vibhash
5. Body
Above the imaginary horizontal plane passing through the openings of the uterine tubes,
expanded dome-like end of the body is called fundus.
The fundus is convex on all sides and covered by the peritoneum.
The body extends from the fundus to the isthmus and contains the uterine cavity.
It is flattened anteroposteriorly and presents anterior and posterior surfaces, and right and
left lateral borders.
Anterior surface: It is flat and directed downward and forward.
It is covered by the peritoneum up to the isthmus, where it is reflected on to the upper
surface of the urinary bladder forming the uterovesical pouch.
Posterior surface: It is convex and directed upward and backward.
It is covered by the peritoneum which extends downward up to the posterior fornix of the
vagina, where it is reflected on the anterior aspect of rectum forming rectouterine pouch (or
pouch of Douglas).
Dr.Vibhash
6. 1 = anterior abdominal wall;
2 = back of the pubis;
3 = superior surface of the bladder;
4 = uterovesical pouch;
5 = posterior surface of the uterus
and posterior fornix;
6 = rectouterine pouch (of
Douglas);
7 = rectum.
Dr.Vibhash
7. Right and left lateral border: Each lateral border is
rounded and related to the uterine artery.
It is nonperitoneal for it provides attachment to
the broad ligament of uterus.
The uterine tube enters the uterus at the upper
end of this border.
Here the round ligament of the uterus is attached
anteroinferior to the tube and the ligament of the
ovary is attached posteroinferior to the tube.
Dr.Vibhash
8. Cervix
It is the lower cylindrical part.
Its lower part projects into the
upper part of the vagina
through its anterior wall.
Thus, the cervix is divided into
two parts:
(a) upper supravaginal part.
(b) lower vaginal part.
Dr.Vibhash
9. Normal Position And Axes Of The Uterus
Normally the uterus lies in position of
anteversion and anteflexion.
Anteversion: The long axis of the cervix is
normally bent forward on the long axis of vagina
forming an angle of about 90°.
This position is called the position of
anteversion.
Anteflexion: The long axis of the body of uterus is
bent forward at the level of isthmus (internal os)
on the long axis of cervix forming an angle of
170°.
This position of the uterus is known as
anteflexion.
Dr.Vibhash
10. Relations Of The Uterus
Anteriorly
The body of uterus is related to the uterovesical pouch and the superior surface of urinary bladder.
The supravaginal portion of cervix is related to the posterior surface of urinary bladder.
The vaginal portion of cervix is related to the anterior fornix of the vagina.
Posteriorly
The body of uterus is related to the rectouterine pouch with coils of ileum and sigmoid colon in it.
The supravaginal portion of cervix is related to the rectouterine pouch with coils of ileum and sigmoid
colon in it.
The vaginal portion of cervix is related to posterior fornix.
Laterally
The body of uterus is related to the broad ligament and uterine artery and vein.
The supravaginal portion of cervix is related to the ureter and uterine artery.
The vaginal portion of cervix is related to the lateral fornices of the vagina.
Dr.Vibhash
12. Cavity Of The Uterus
The cavity of uterus is small in comparison
to its size due to its thick muscular wall.
It is divided into two parts: cavity of the
body and cavity of the cervix.
Cavity of the Body (Uterine Cavity Proper):
It is a triangular in coronal section.
The apex of this cavity is continuous below
with the cervical canal through internal os.
The implantation commonly occurs in the
upper part of its posterior wall.
It is slit in sagittal section, because the
uterus is compressed anteroposteriorly and
its anterior and posterior walls are almost in
contact.
Dr.Vibhash
13. Cavity Of The Uterus….
Cavity of the Cervix (Cervical Canal):
It is a spindle-shaped canal, being broader in the
middle and narrow at the ends.
It communicates anterosuperiorly with the cavity
of body of uterus through internal os and
inferiorly with the cavity of vagina through
external os (ostium uteri).
In nulliparous women (women who have not
given birth to a baby) the external os is small and
circular,
whereas in multiparous women (women who
have given birth to two or more babies) the
external os is large and transverse, and presents
anterior and posterior lips.
Dr.Vibhash
14. Ligaments
The ligaments of the uterus are classified into two types: false and true.
The false ligaments are peritoneal folds whereas the true ligaments are fibromuscular
bands.
The false ligaments do not provide support to the uterus while true ligaments provide
support to the uterus.
Dr.Vibhash
15. Arterial Supply
The uterus is supplied mainly by two
uterine arteries and partly by two ovarian
arteries.
The uterine artery is a branch of anterior
division of internal iliac artery.
It crosses the ureter from above lateral to
the cervix above the lateral to the fornix
of the vagina.
Then it ascends along the side of the
uterus. At the superolateral angle of uterus
it turns laterally, runs along the uterine
tube, and terminates by anastomosing
with the ovarian artery.
Dr.Vibhash
16. Venous Drainage
The veins of the uterus correspond to arteries.
They form venous plexus along the lateral borders of the uterus,
which drains into internal iliac veins through uterine and vaginal
veins.
Dr.Vibhash
17. Lymphatic Drainage
The lymphatic drainage of the uterus is clinically important because uterine cancer spreads
through lymphatics.
1. From fundus and upper part of the body: most of the lymphatics drain into pre- and para-
aortic lymph nodes along the ovarian vessels. However, a few lymphatic vessels from the
lateral angles of the uterus drain into superficial inguinal lymph nodes along the round
ligaments of the uterus.
2. From the lower part of the body: the lymph vessels drain into external iliac nodes via broad
ligament.
3. From cervix: on each side the lymph vessels drain in three directions:
a) Laterally, the lymph vessels drain into external iliac and obturator nodes by passing parametric
tissue, few of these vessels are intercepted by paracervical nodes.
b) Posterolaterally, the lymph vessels drain into internal iliac nodes by passing along the uterine
vessels.
c) Posteriorly, the lymph vessels drain into sacral nodes by passing along the uterosacral
Dr.Vibhash
19. Nerve Supply
The uterus is richly innervated by both sympathetic and
parasympathetic fibres.
1. The sympathetic fibres are derived from T12–L2 spinal
segments. The sympathetic fibres cause uterine contraction and
vasoconstriction.
2. The parasympathetic fibres are derived from S2–S4 spinal
segments. The parasympathetic fibres inhibit the uterine muscles
and cause vasodilatation.
Dr.Vibhash
20. Supports Of The Uterus
The uterus is kept in position and prevented from sagging down by a number of
structures providing support to it.
The supports of the uterus are subdivided into two types: chief or primary supports and
accessory or secondary supports.
Dr.Vibhash
22. Secondary Supports:
1. Broad ligaments .
2. Uterovesical fold of peritoneum.
3. Rectovaginal fold of peritoneum.
Dr.Vibhash
23. Clinical Correlation
Cervical carcinoma: It is the most common cancer in females (11%).
The second commonest cancer in females is breast cancer (about 8%).
It is rare before 20 years of age and reaches its peak between the ages
45 and 55 years. 80% cervical cancers are squamous cell carcinoma
and are related to sexual activity. Early sexual exposure and
promiscuity are prominent factors.
It spreads directly to adjacent structures and metastasizes via
lymphatics to pelvic lymph nodes and then to the preaortic and para-
aortic lymph nodes.
Caesarean section: It is the surgical procedure for delivering the baby by
cutting open the abdomen and uterus in cases where vaginal delivery is
not possible.
Dr.Vibhash
24. Clinical Correlation..
Prolapse of the Uterus
The great importance of the tone of the levatores ani muscles in
supporting the uterus has already been emphasized.
The importance of the transverse cervical, pubocervical, and
sacrocervical ligaments in positioning the cervix within the pelvic cavity
has been considered.
Damage to these structures during childbirth or general poor body
muscular tone may result in downward displacement of the uterus called
uterine prolapse
Dr.Vibhash