anatomy of uterus

1. Anatomy of Uterus &
its Appendages
DR. SRAVANI KOMMURU,1ST YR PG
DEPT OFOBSTETRICS &GYNAECOLOGY
NRIIMS

2. UTERUS:
thick-walled, muscular organ with narrow lumen.
present in the pelvis between the urinary bladder and
the rectum.
Superiorly, on each side-- uterine tube
 inferiorly --vagina.
Shape and Size :
pear-shaped, being flattened
anteroposteriorly
Measurements:
Length: 3 inches (7.5 cm).
Breadth (at fundus): 2 inches (5 c
m
)
.
Thickness: 1 inch (2.5 cm).

3. PARTSOFTHEUTERUS:
DIvided into two main parts:
(a) large upper pear-shaped part—thebody.
(b) small lower cylindrical part—the cervix.
The body forms upper 2/3rd and cervix
forms the lower 1/3rd .
Junction between body and cervix is a
circular constriction called isthmus (0.5cm).
The point of fusion between the uterine tube
and body is called cornu of the uterus.

4. BODY
Above the openings of the uterinetubes,dome-like end is
called fundus.
 smooth muscle tissue of body is 2.5cm thick
 Outer –longitudinal fibres,
 middle- crisscross-which contain openings of
blood vessels- living ligature.
 inner –circular muscle fibres.
ISTHMUS:
• Forms LUS(LOWER UTERINE SEGMENT), at
24weeks & completes at labour.
• At term[ 70% isthmus &30%cervix] forms LUS
measures 5cm
• In labour, LUS measures 10cm

5. Anterior surface: flat , directed downward& forward.
Covered by the peritoneum up to isthmus,
reflects on the upper surface of urinary
bladder as uterovesicalpouch.
Anterior relations:
Body -uterovesical pouch & superior surface
of urinary bladder.
Supravaginal portion of cervix - posterior
surface of urinary bladder –loose areolar
tissue.
vaginal portion of cervix -anterior fornix of
the vagina.

6. Posterior surface:
• covered by the peritoneum -to posterior fornix.
• reflects- anterior aspect of rectum forming
rectouterine pouch (or pouch of Douglas).
Posterior relations:
• Body - rectouterine pouch with coils of ileum
and sigmoid colon.
• Supravaginal portion of cervix -rectouterine
pouch with coils of ileum and sigmoid colon.
• Vaginal portion of cervix - posterior fornix.

7. Right and left lateral border:
rounded and related to the uterine artery
 provides attachment to the broad ligament of uterus.
 round ligament is attached anteroinferior to the tube
 ligament of the ovary is attached posteroinferior to the
tube.
 Mackendrot ligament- from internal os down to
supravaginal cervix to lateral vaginal wall.
Laterally
Body of uterus - broad ligament , uterine artery & vein.
Supravaginal portion of cervix - ureter & uterine artery.
Vaginal portion of cervix - lateral fornices of the vagina.

8. BROAD LIGAMENTS:
Double layer peritoneum,
Side of uterus to lateral wall of pelvis.
2 layers:
posterior layer:
forms mesovarium
pierced by lateral end of fallopian tube
anterior layer: free
CONTENTS OF BROAD LIGAMENT:
• Fallopian tubes
• Ovarian vessels
• Uterine vessels
• Round ligament &ovarian ligament
• Epoophoron & paroophoron
• Ovary attatched to posterior layer

9. Cervix
Cylindrical, measures 2.5cm
cervix is divided into
two parts:
(a) upper supravaginal part.
(b) lower vaginal part.
• Cervical wall made of outer stroma- connective tissue containing collagen; only 10-15% smooth
muscle
• Secretions- alkaline,thick ,scanty- rich in mucoprotein, fructose,NaCl.

10. Cavity Of The Uterus
small in comparison to its size due to thick
muscular wall.
 Base above ,apex below:
Cavity of the Body (Uterine Cavity Proper):
 It is a triangular in coronalsection.
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 both walls are almostin contact.

11. Cavity of the Cervix (Cervical
Canal):
It is a spindle-shaped canal, broader in
middle, narrow at the ends.
nulliparous women-external os is small
and circular.
multiparous women - external os is
large &transverse, and presents
anterior and posterior lips.
• ANATOMICAL INTERNAL OS:
• HISTOLOGICAL INTERNAL OS: slight change in epithelium, lies below
anatomical internal os ,distance from isthmus 0.5cm

12. Ligaments
The ligaments of the uterus are classified into two types: false and true.
The false ligaments are peritoneal folds whereas the true ligaments arefibromuscular
bands.
The false ligaments do not provide support to the uterus while true ligamentsprovide
support to the uterus.

13. Supports Of The Uterus:
 UPPER:
1.ROUND LIGAMENT – Fibrous chord (12cm)
from uterine end ->internal inguinal ring -
>inguinal canal ->external inguinal ring->labia
majora
• Hooks around Inferior epigastric artery
• Peritoneum-processus vaginalis-canal of
nuck
2.BROAD LIGAMENT
 MIDDLE:
1.TRANSVERSE CERVICAL LIGAMENT-
supravaginal cervix &vaginal vault ->parietal
fascia on pelvic wall
2.PUBOCERVICAL-cervix&vagina->pubic

14.  LOWER:
3.UTEROSACRAL-cervix ->S2 vertebra
• maintain anteversion of uterus.
• Hypertrophy-pregnancy, atropy-after menopause
1.UROGENITAL DIAPHRAGM:
• Two layered fibrous sheath between ischiopubic rami
• Inserted posteriorly b/w 2 ischial tuberosities.

15. 2 .LEVATOR ANI:
3.PERINEAL BODY:
• Pyramid shaped fibromuscular mass
4*4Cm,
• Separates vulva,vagina from anus
• Many blend –a)pubococcygeus
b)superficial &deep transverse perinei
c)eternal anal spinchter
d)bulbocavernosus e)posterior border

16. DELANCEY’S 3 LEVELS OF SUPPORT:

17. 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 bent
on long axis ofvagina at an angle of 90°.
Anteflexion: The long axis of the body of uterus is
bent at the level of isthmus (internal os) on
long axis of cervix forming an angle of 170°.

18. • Fundus pointing towards bladder(anteriorly)=
ANTEFLEXION
• ANGLE of cervix &vagina= straightened
obtuse angle =RETROVERSION
• Fundus pointing towards rectum =
RETROFLEXION

19. Arterial Supply
The uterus - two uterine arteries and
partly by twoovarian arteries.
The uterine artery is a branch ofanterior
division of internal iliac artery.
It crosses the ureter from
above,(WATER UNDER THE BRIDGE)
 Atthe superolateral angle of uterus it
turns laterally, runs along the uterine
tube, and terminates by anastomosing
with the ovarian artery.

20. 1. Arcuate branches:surface to outer 1/3rd of
myometrium
2. Radial branches: inner 2/3rd of myometrium
3. Basal arteries: basal part of endometrium
4. Spiral arteries:superficial part of endometrium
UTERINE ARTERY &ITS BRANCHES:
BLOOD SUPPLY OF CERVIX:
• DESCENDING CERVICAL ARTERIES AT 3’0 & 9’0 POSITIONS

21. VENOUS DRAINAGE :
They form venous plexus(pampiniform plexuses) along with ovarian veins
drains into internal iliac veins uterine veins
1. The sympathetic fibres -T10–L1 spinal segments.
somatic pain distribution in abdomen area of T10-L8
The sympathetic fibres cause uterine contraction and vasoconstriction.
2. The parasympathetic fibres - S2–S4 spinal segments ends in GANGLION
FRANKENHAUSER. The parasympathetic fibres inhibit the uterinemuscles and
cause vasodilatation.
NERVE SUPPLY:

22. Dr.Vibhash

23. Histology
SINGLE LAYER OF COLUMNAR
EPITHELIUM & SIMPLE TUBULAR
GLANDS
SINGLE LAYER OF COLUMNAR
EPITHELIUM &COMPOUND
RACEMOSE GLANDS
STRATIFIED SQUAMOUS
EPITHELIUM

24. SQUAMO COLUMNAR JUNCTION:
• Physiological- metaplasia
• As age increases, SCJ move inwards into endocervix.
• New SCJ arise from external os
• Transformation zone is most dynamic area, pap smear taken from it.

25. Ovary:
 Each ovary is whitish in color,3*2*1cm,intraperitoneal
 located along lateral wall of the uterus in a region called ovarian fossa.
 The ovarian fossa is an area of 4 cm x 3 cm x 2 cm in size.The ovaries are
surrounded by a capsule, and have an outer cortex and an inner medulla.

26. Ovary is attatched to lateral pelvic wall by infundibulo-pelvic ligament carries blood vessels.
Volume of ovary:
• In reproductive age normal upto 20cc (avg 7-8cc)
• Postmenopausal age normal upto10cc(avg 3-4cc)

27. HISTOLOGY OF OVARY
• CAPSULE: lining
epithelium- single layer of
cuboidal epithelium
• CORTEX: contains different
stages of follicles
• MEDULLA: vascular layer
• No. of oocytes at birth 2
million
• At puberty, 4lakhs
• Ovulate during life 100,
• Undergo atresia-
1000/every month

28. BLOOD SUPPLY:
• Ovarian artery –branch of Abdominal Aorta at L2
• Ovarian vein -on left side drains into Left Renal vein
• -on right side drains into IVC
LYMPHATIC DRAINAGE:
NERVE SUPPLY:
• Sympathetic
T10,T11 by
Aorticorenal
plexuses.(OVARIES
ARE SENSITIVE TO
MANUAL
SQUEEZING)
• Parasympathetic
by left and right
inferior

29. FALLOPIAN TUBES
ITS different segments are (lateral to medial):
• the infundibulum with its
associated fimbriae near the ovary
• the ampullary(5cm) region is the major
portion of the lateral tube(WIDEST 6mm),
• the isthmus(3cm) segment is the narrower
part(1mm)
• the interstitial(1-2cm) (also Known as
intramural) part is narrowest(0.7mm).
• The ostium is the point where the tubal canal
meets the peritoneal cavity,
• The average length of a fallopian tube is 11-
12 cm.

30. The uterine tubes receive both sympathetic
and parasympathetic innervation via nerve
fibres from the ovarian and uterine
(pelvic) plexuses. Sensory afferent fibres
run from T11- L1.
NERVE SUPPLY
BLOOD SUPPLY:
• Dual blood supply
• Medial 2/3rd- uterine artery
• Lateral 1/3rd-ovarian artery
LYMPHATIC DRAINAGE:
• Ostia &interstitial part : Superficial
Inguinal LN
• Rest of tube: Para Aortic LN
DECREASED PERISTALSIS IS RISK FOR ECTOPIC
PREGNANCY.

31. REFERENCES:
1. GRAY’S ANATOMY .
2. MUDALIAR & MENON TEXTBOOK OF OBSTETRICS.